SwePub - sökning: WFRF:(Eklund Per)

Numrering	Referens	Omslagsbild	Hitta
1.	Alami, Jones, et al. (författare) Phase tailoring of Ta thin films by highly ionized pulsed magnetron sputtering 2007 Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 515:7-8, s. 3434-3438 Tidskriftsartikel (refereegranskat)abstract Ta thin films were grown on Si substrates at different inclination angles with respect to the sputter source using high power impulse magnetron sputtering (HIPIMS), an ionized physical vapor deposition technique. The ionization allowed for better control of the energy and directionality of the sputtered species, and consequently for improved properties of the deposited films. Depositions were made on Si substrates with the native oxide intact. The structure of the as deposited films was investigated using X-ray diffraction, while a four-point probe setup was used to measure the resistivity. A substrate bias process-window for growth of bcc-Ta was observed. However, the process-window position changed with changing inclination angles of the substrate. The formation of this low-resistivity bcc-phase could be understood in light of the high ion flux from the HIPIMS discharge.
2.	Azina, Clio, et al. (författare) Deposition of MAX phase-containing thin films from a (Ti,Zr)(2)AlC compound target 2021 Ingår i: Applied Surface Science. - : Elsevier. - 0169-4332 .- 1873-5584. ; 551 Tidskriftsartikel (refereegranskat)abstract This work reports on sputter depositions carried out from a compound (Ti,Zr)(2)AlC target on Al2O3(0 0 0 1) substrates at temperatures ranging between 500 and 900 degrees C. Short deposition times yielded 30-40 nm-thick Al-containing (Ti,Zr)C films, whereas longer depositions yielded thicker films up to 90 nm which contained (Ti,Zr)C and intermetallics. At 900 degrees C, the longer depositions led to films that also consisted of solid solution MAX phases. Detailed transmission electron microscopy showed that both (Ti,Zr)(2)AlC and (Ti,Zr)(3)AlC2 solid solution MAX phases were formed. Moreover, this work discusses the growth mechanism of the thicker films, which started with the formation of the mixed (Ti,Zr)C carbide, followed by the nucleation and growth of aluminides, eventually leading to solid state diffusion of Al within the carbide, at the highest temperature (900 degrees C) to form the MAX phases.
3.	Carlsson, Per, 1951-, et al. (författare) National Model for Transparent Vertical Prioritisation in Swedish Health Care 2007 Rapport (övrigt vetenskapligt/konstnärligt)abstract The proposed national model described in this report has been developed by a working group comprised of staff from the National Board of Health and Welfare, the National Centre for Priority Setting in Health Care, and other organisations involved in vertical prioritisation – including the Östergötland County Council, Stockholm County Council, Västra Götaland, the Health Services Region of Southern Sweden, the Swedish Society of Medicine, the Swedish Society of Nursing, and the Swedish Association of Health Professionals. Throughout the process of designing the model, the Swedish Federation of Occupational Therapists and the Swedish Association of Registered Physiotherapists were regularly informed and given opportunities to review and comment on the proposal. Furthermore, the report was reviewed and discussed at a meeting with invited representatives from the other county councils, the Pharmaceutical Benefits Board, and several professional interest groups. Viewpoints were also obtained at a seminar arranged by PrioNet, a network of individuals interested in prioritisation.Potentially, the working model described in Chapter 4 could be used in any context where vertical prioritisation takes place, e.g. activities arranged by the state, county councils, municipalities, hospital departments, and professional groups.This report is designed to be a useful tool for those working on development projects in priority setting. We believe that the contents must be adapted, with the help of relevant examples and some simplifications; to fit the specific needs of different projects or groups. The text must also be adapted to a target group’s knowledge and previous experience in dealing with transparent priority setting. It must be the responsibility of each provider and other affected organisation to adapt the material to the given situation and project. The National Centre for Priority Setting in Health Care, the National Board of Health and Welfare, and others who have participated actively in this effort can be helpful to various target groups in adapting this report.When and how to engage in practically implementing vertical prioritisation are questions that need to be answered at the local level. Primarily, it is the duty of the local authorities/providers to take responsibility for implementation. Professional organisations also play an important role. Public agencies, universities, and knowledge centres should be sources of support for the local authorities/providers.The Riksdag’s resolution on prioritisation served as the foundation for developing the model.Where there are areas of uncertainty in how to translate these guidelines in practice, or where practical implementation might conflict with the principles, we have pointed this out.Our conclusions and proposals are the following:When facing a choice – regardless of whether it involves allocating new resources for different purposes, or to implement cutbacks – it can be advantageous to rank the possible choices in order of priority. In our model, only the relevant options can be ranked by priority. The consequences of this ranking are not obvious at the outset, but can serve as a basis either to allocate more resources or ration by some means.In vertical prioritisation, it is advantageous to organise the prioritization process starting from a general categorisation of health problems/disease groups. As a rule, these categories cover many organisational units/clinical departments, specialties, or professional groups, thus providing a more multidimensional view of the problem. Furthermore, this allows the process to start from a patient/population perspective, which appears to be more goal-oriented than an organisational/staff perspective.That which is ranked, i.e. one of the choices, we refer to as a prioritization object. We suggest that prioritisation objects consist of different combinations of health conditions and interventions.1 When deciding on the appropriate level of detail, the decision must be based on the context in which prioritisation is carried out. A starting point would be to focus on typical cases, large-volumes services, and controversial care.All forms of vertical prioritisation should be based on the ethical principles that the Riksdag decided should apply in prioritising health services. However, these ethical principles must be made known, clarified, and perhaps complemented before they can be applied to practical priority setting. Furthermore, we believe that the Riksdag’s four so-called priority groups should not be part of the model.The human dignity principle, i.e. that all people should have equal value and equal rights to care irrespective of their personal characteristics and function in society, is the undisputed cornerstone in priority setting. When personal characteristics such as age, gender, lifestyle, or function of a group are expressions of the presence of special needs, so that benefits of the interventions are different, these personal characteristics could be addressed in a priority at the group level. Further discussion is needed regarding the question of how external effects (i.e. the effects of an intervention on families and groups other than the individual directly affected by the intervention) should be valued in priority setting.The concept of need in health care includes both the severity level of the condition and the expected benefits of intervention. As a patient, one needs only those interventions that can be expected to yield benefits. Based on this definition of need, a person does not need an intervention that does not improve health and quality of life, i.e. an intervention with no benefit. In such cases, health services have a responsibility to refer people who seek care for some type of problem, to other appropriate services.The Riksdag’s guidelines regarding the cost-effectiveness principle (applied to individual patients) are too limited to provide guidance for vertical prioritisation at the group level. From the outset, the Government’s bill (Priority Setting in Health Care) highlighted the importance of differentiating a cost-effectiveness principle that applied to choices among various interventions for the individual patient (where the principle can be applied as the Commission of Inquiry proposed) and the aim of health services to achieve high cost-effectiveness in health care generally. Here we also refer to the Riksdag’s directive to the Pharmaceutical Benefits Board. In its decisions on subsidising (prioritising) a drug, the Board should determine, e.g. whether the drug is cost effective from a societal perspective, which requires comparing the patient benefits of the drug to its cost. In such decisions, the cost effectiveness should be considered along with the needs and solidarity principle and the human dignity principle.The proposed working model essentially concurs with the working model used by the National Board of Health and Welfare in developing national guidelines. In describing a national working model, it is not possible to include every aspect that might be considered. Hence, one must start from the model and decide which other relevant aspects should be included. For instance, the International Classification on Functioning, Disability, and Health (ICF) can be used as guidance to describe the severity of health conditions.Due to the wealth of variety in outcome measures for different activities, and the limited experience in working with explicit threshold values, we believe would be premature to recommend standardised categories, e.g. risk levels. However, it is important that those working with prioritization describe their reasoning. Primarily, the categories applied by the Swedish Council on Technology Assessment in Health Care (SBU) to grade the scientific evidence of an intervention’s effects should be used. Local prioritisation projects with limited resources at their disposal should describe (text) their appraisal of the scientific evidence and reference the scientific sources used. The strength of evidence should be expressed in numbers only when supporting a conclusion of a systematic review by SBU, or other literature reviews of good quality.Prioritisation projects having access to health economic evaluation should, until further notice, adhere to the approach used by the National Board of Health and Welfare and present cost-effectiveness on a scale from low to very high cost per life-year gained or cost per quality-adjusted life-year. Economic evidence should be presented according to the principles applied by the National Board of Health and Welfare. In local projects with limited resources, or problems in consistently acquiring information on cost effectiveness, we recommend that the authors at least discuss cost effectiveness in cases where the priority ranking would be decisively affected when costs are weighed in.A 10-level ranking list should be used. The ranking list should be complemented by a “don’t do” list for methods that should not be used at all, or not used routinely, and a research and development (R&D) list for methods where the evidence still insufficient to motivate their use in standard practice. In the absence of an objective quantitative/mathematical method, a qualitative method should be used in the appraisal. Here too, we believe that it is not yet possible to establish standard criteria to determine within which ranking level a prioritisation object should fall.Results should be presented as a ranking list. The parameters used as a basis for prioritisation should also be presented in a uniform manner in ranking lists that are shared with other parties. For pedagogic reasons, details concerning language and format need to be adapted to the respective target groups.Thresholds for what constitutes an acceptable coverage of need (care quality, volume, and percentage of the patient group with access to services) a
4.	Carlsson, Per, 1951-, et al. (författare) Nationell modell för öppna vertikala prioriteringar inom svensk hälso- och sjukvård 2007 Rapport (övrigt vetenskapligt/konstnärligt)abstract En arbetsgrupp med personer från Socialstyrelsen och PrioriteringsCentrum, andra organisationer som arbetat med vertikala prioriteringar såsom Landstinget i Östergötland, Stockholms läns landsting, Västra Götaland, Södra sjukvårdsregionen, Svenska Läkaresällskapet, Svensk sjuksköterskeförening och Vårdförbundet har tagit fram detta förslag. Förslaget har fortlöpande förankrats hos Förbundet Sveriges Arbetsterapeuter och Legitimerade Sjukgymnasters Riksförbund som kunnat lämna synpunkter på utformningen av odellen.Dessutom har rapporten varit föremål för granskning och diskussion vid ett möte med inbjudna representanter från övriga landsting, Läkemedelsförmånsnämnden och flera yrkesorganisationer. Synpunkter har också inkommit från ett seminarium som arrangerades av PrioNet, ett nätverk av personer med intresse för prioriteringar.Den arbetsmodell som beskrivs i kapitel 4 ska kunna användas i alla sammanhang där vertikala prioriteringar sker såsom aktiviteter som arrangeras av staten, landsting, kommuner, kliniker, professionella grupper eller motsvarande.Rapporten är skriven på ett sådant sätt att den ska kunna användas i första hand som ett stöd till dem som bedriver utvecklingsarbete rörande prioriteringar. Vi tror att innehållet måste anpassas till olika verksamheter eller personalgruppers specifika behov med hjälp av kompletterande exempel och vissa förenklingar. Texten måste givetvis också anpassas till de kunskaper och tidigare erfarenheter som den aktuella målgruppen har när det gäller arbete med öppna prioriteringar. Sådana situations- och verksamhetsanpassade versioner måste det åligga varje sjukvårdshuvudman och andra berörda organisationer att utarbeta. PrioriteringsCentrum, Socialstyrelsen och andra parter som deltagit aktivt i detta arbete kan givetvis vara behjälpliga i arbetet med att bearbeta denna rapport för olika målgrupper.Frågan om när och hur arbetet med vertikala prioriteringar ska bedrivas i praktiken kan också endast besvaras lokalt. Det är i första hand ett nsvar för huvudmännen att ta ansvar för implementeringen. Professionella organisationer har också en viktig roll. Myndigheter, universitet och kunskapscentra ska vara ett stöd till huvudmännen.Utgångspunkten i modellutvecklingen är Riksdagens beslut om prioriteringar. När det finns oklarheter om hur dessa riktlinjer ska omsättas i praktiken eller att praktiken kan förefalla i konflikt med principerna har vi påpekat detta.När man står inför ett val - oavsett om det handlar om att fördela nya resurser till olika ändamål eller att genomföra besparingar - kan det vara en fördel att kunna rangordna tänkbara valmöjligheter i enprioriteringsordning. I vår modell innebär prioritering enbart att de relevanta alternativen rangordnas. Konsekvenserna av denna rangordning är inte på förhand given utan kan ligga till grund såväl för tillskott av resurser som för ransonering av något slag.Vid en vertikal prioritering är det en fördel att organisera prioriteringsarbetet så att det utgår från en grov uppdelning i hälsoproblem/sjukdomsgrupper. En sådan uppdelning innebär i regel att flera organisationsenheter/kliniker, specialiteter eller yrkesgrupper berörs och man får en mer allsidig belysning av problemet. Dessutom utgår man från ett patient/befolkningsperspektiv vilket förefaller mer ändamålsenligt än ett organisatoriskt/personalperspektiv.Det som rangordnas och som någon väljer mellan benämner vi prioriteringsobjekt. Vi föreslår att prioriteringsobjektet utgörs av olika kombinationer av hälsotillstånd och åtgärder1. När det gäller att bestämma en lämplig detaljeringsgrad måste det avgöras utifrån sammanhanget prioriteringar ska göras i. En utgångspunkt är att fokusera på typfall, vård som representerar stor volym och kontroversiell vård.Alla former av vertikala prioriteringar ska baseras på de etiska principer som riksdagen beslutat ska gälla vid prioriteringar inom hälso- och sjukvården. De etiska principerna behöver dock göras kända, förtydligas och eventuellt kompletteras för att kunna omsättas i praktiska prioriteringar. Vidare anser vi att riksdagens fyra så kallade prioriteringsgrupper inte ska ingå i modellen.Människovärdesprincipen, som innebär att alla människor bör ha lika värde och samma rätt till vård oberoende av personliga egenskaper och funktioner i samhället, är den självklara utgångspunkten vid prioriteringar. När personliga egenskaper såsom ålder, kön, livsstil eller funktion hos en grupp är ett uttryck för att speciella behov föreligger så att nytta med insatserna blir olika ska de personliga egenskaperna kunna beaktas i en prioritering på gruppnivå. Frågan om hur externa effekter, d v s effekten av en insats för närstående och andra grupper än den individ som är direkt berörd av insatsen, ska värderas vid en prioritering behöver diskuteras ytterligare.Med behov av hälso- och sjukvård menas både tillståndets svårighetsgrad och den förväntade nyttan av en åtgärd. Som patient har man endast behov av sådana vårdåtgärder som man förväntas ha nytta av. Motsatt gäller att en människa enligt detta sätt att definiera behov inte behöver åtgärder som inte förbättrar hälsan och livskvaliteten, sådana som hon inte har nytta av. Här har givetvis hälso- och sjukvården ett ansvar att lotsa människor de kommer i kontakt med, och som far illa på något sätt, till andra lämpliga aktörer.Riksdagens riktlinjer, när det gäller kostnadseffektivitetsprincipen (tillämpad för enskilda patienter), är för begränsad för att vägleda vid vertikala prioriteringar som gäller prioritering på gruppnivå. Regeringen konstaterade redan i prioriteringspropositionen att det är angeläget att skilja på en kostnadseffektivitetsprincip som gäller val mellan olika åtgärder för den enskilde patienten (där principen kan tillämpas som utredningen föreslår) och på hälso- och sjukvårdens strävan efter en hög kostnadseffektivitet när det gäller vårdens verksamhet i allmänhet. Här stödjer vi oss på Riksdagens direktiv till Läkemedelsförmånsnämnden. Nämnden ska vid beslut om subvention (prioriteringar) av ett läkemedel bl a bedöma om det är kostnadseffektivt i ett samhälleligt perspektiv, vilket innebär att man ställer patientnyttan av läkemedlet mot kostnaden. I bedömningen ska kostnadseffektiviteten vägas samman med behovs- och solidaritetsprincipen och människovärdesprincipen.Den föreslagna arbetsmodellen överensstämmer i allt väsentligt med den arbetsmodell som används av Socialstyrelsens vid framtagning av nationella riktlinjer. Det är inte möjligt att rymma alla aspekter som kan vara aktuella att beakta vid beskrivning av en nationell arbetsmodell. Man måste därför utgå från modellen och fundera på vilka andra relevanta aspekter som dessutom bör vägas in. T ex kan den internationella klassifikationen för funktionsförmåga (ICF) användas som vägledning.På grund av den stora variationsrikedomen av effektmått i olika verksamheter och de begränsade erfarenheter som finns att arbeta med sådana explicita gränsvärden anser vi att det är för tidigt att rekommendera en enhetlig indelning i t ex risknivåer. Det är dock viktigt att de som arbetar med prioriteringar redovisar hur de har resonerat.SBU:s klassifikation för att gradera den vetenskapliga evidensen för en åtgärds effekt bör användas i första hand. Lokala prioriteringsprojekt med begränsade resurser till sitt förfogande föreslås redovisa bedömningen av det vetenskapliga underlaget med ord och referera till det kunskapsunderlag som använts. Evidensstyrkan bör endast uttryckas med siffror då man stöder en slutsats på en systematisk kunskapsöversikt från SBU eller en annan översikt av god kvalitet.Prioriteringsarbeten där hälsoekonomiska data finns tillgängliga bör tills vidare ansluta till Socialstyrelsens arbetssätt och ange kostnadseffektivitet i en skala från låg till mycket hög kostnad per vunnet levnadsår eller kostnad per kvalitetsjusterat levnadsår. Den hälsoekonomiska evidensen bör redovisas i enlighet med de principer som Socialstyrelsen tillämpar. I lokala projekt med små resurser eller svårigheter att konsekvent få fram uppgifter om kostnadseffektivitet rekommenderar vi att man åtminstone resonerar om kostnadseffektivitet i de fall prioriteringsordningen på ett avgörande sätt påverkas när kostnaderna vägs in.Tio nivåer bör användas för rangordning samt att rangordningslistan kompletteras med en ”icke-göra-lista” för metoder som inte bör utföras alls eller rutinmässigt samt en FoU-lista för metoder där det fortfarande saknas tillräcklig evidens för att kunna motivera ett införande i rutinsjukvården. Sammanvägningen sker företrädesvis med en kvalitativ metod i avsaknad av en invändningsfri kvantitativ/matematisk metod. Likaså tror vi att det för närvarade inte är möjligt att fastställa entydiga kriterier som avgör inom vilken rangordningsnivå ett prioriteringsobjekt ska hamna.Resultatet bör presenteras i form av en rangordningslista. De parametrar som ligger till grund för prioriteringen bör också på ett enhetligt sätt redovisas i sådana rangordningslistor som visas för andra. I detalj kan språket och utseendet av pedagogiska skäl behöva anpassas för respektive målgrupp.Gränser för vad som är acceptabel behovstäckning (vårdkvalitet, mängd liksom andel av de i patientgrupp som får tillgång till insatsen) är en regional och lokal fråga och ingår därför inte i den nationella modellen.
5.	Carlsson, Per, et al. (författare) Nationell modell för öppna vertikala prioriteringar inom svensk hälso- och sjukvård 2007 Rapport (övrigt vetenskapligt/konstnärligt)
6.	Ding, Haoming, et al. (författare) Chemical scissor-mediated structural editing of layered transition metal carbides 2023 Ingår i: Science. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075 .- 1095-9203. ; 379:6637, s. 1130-1135 Tidskriftsartikel (refereegranskat)abstract Intercalated layered materials offer distinctive properties and serve as precursors for important two-dimensional (2D) materials. However, intercalation of non-van der Waals structures, which can expand the family of 2D materials, is difficult. We report a structural editing protocol for layered carbides (MAX phases) and their 2D derivatives (MXenes). Gap-opening and species-intercalating stages were respectively mediated by chemical scissors and intercalants, which created a large family of MAX phases with unconventional elements and structures, as well as MXenes with versatile terminals. The removal of terminals in MXenes with metal scissors and then the stitching of 2D carbide nanosheets with atom intercalation leads to the reconstruction of MAX phases and a family of metal-intercalated 2D carbides, both of which may drive advances in fields ranging from energy to printed electronics.
7.	Ding, Haoming, et al. (författare) Synthesis of MAX phases Nb2CuC and Ti2(Al0.1Cu0.9)N by A-site replacement reaction in molten salts 2019 Ingår i: Materials Research Letters. - : Taylor & Francis. - 2166-3831. ; 7:12, s. 510-516 Tidskriftsartikel (refereegranskat)abstract New MAX phases Ti2(AlxCu1−x)N and Nb2CuC were synthesized by A-site replacement by reacting Ti2AlN and Nb2AlC, respectively, with CuCl2 or CuI molten salt. X-ray diffraction, scanning electron microscopy, and atomically resolved scanning transmission electron microscopy showed complete A-site replacement in Nb2AlC, which lead to the formation of Nb2CuC. However, the replacement of Al in Ti2AlN phase was only close to complete at Ti2(Al0.1Cu0.9)N. Density-functional theory calculations corroborated the structural stability of Nb2CuC and Ti2CuN phases. Moreover, the calculated cleavage energy in these Cu-containing MAX phases are weaker than in their Al-containing counterparts.The preparation of MAX phases Nb2CuC and Ti2(Al0.1Cu0.9)N were realized by A-site replacement in Ti2AlN and Nb2AlN, respectively.
8.	Eklund, A, et al. (författare) Long-term cost-minimization analysis comparing laparoscopic with open (Lichtenstein) inguinal hernia repair. 2010 Ingår i: The British journal of surgery. - : Oxford University Press (OUP). - 1365-2168 .- 0007-1323. ; 97:5, s. 765-71 Tidskriftsartikel (refereegranskat)abstract Laparoscopic surgery has emerged as a new treatment modality for inguinal hernia repair. The aim of the present study was to analyse its long-term costs in relation to those of open repair.
9.	Eklund, Per, et al. (författare) Layered ternary M(n+1)AX(n) phases and their 2D derivative MXene: an overview from a thin-film perspective 2017 Ingår i: Journal of Physics D. - : IOP PUBLISHING LTD. - 0022-3727 .- 1361-6463. ; 50:11 Forskningsöversikt (refereegranskat)abstract Inherently and artificially layered materials are commonly investigated both for fundamental scientific purposes and for technological application. When a layered material is thinned or delaminated to its physical limits, a two-dimensional (2D) material is formed and exhibits novel properties compared to its bulk parent phase. The complex layered phases known as MAX phases (where M = early transition metal, A = A-group element, e.g. Al or Si, and X = C or N) are an exciting model system for materials design and the understanding of process-structure-property relationships. When the A layers are selectively etched from the MAX phases, a new type of 2D material is formed, named MXene to emphasize the relation to the MAX phases and the parallel with graphene. Since their discovery in 2011, MXenes have rapidly become established as a novel class of 2D materials with remarkable possibilities for composition variations and property tuning. This article gives a brief overview of MAX phases and MXene from a thin-film perspective, reviewing theory, characterization by electron microscopy, properties and how these are affected by the change in dimensionality, and outstanding challenges.
10.	Eklund, Per, et al. (författare) Structural, electrical, and mechanical properties of nc-TiC/a-SiC nanocomposite thin films 2005 Ingår i: Journal of Vacuum Science & Technology B. - : American Vacuum Society. - 1071-1023 .- 1520-8567. ; 23:6, s. 2486-2495 Tidskriftsartikel (refereegranskat)abstract We have synthesized Ti–Si–C nanocomposite thin films by dc magnetron sputtering from a Ti3SiC2 compound target in an Ar discharge on Si(100), Al2O3(0001), and Al substrates at temperatures from room temperature to 300 °C. Electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy showed that the films consisted of nanocrystalline (nc-) TiC and amorphous (a-) SiC, with the possible presence of a small amount of noncarbidic C. The growth mode was columnar, yielding a nodular film-surface morphology. Mechanically, the films exhibited a remarkable ductile behavior. Their nanoindentation hardness and E-modulus values were 20 and 290 GPa, respectively. The electrical resistivity was 330 µ cm for optimal Ar pressure (4 mTorr) and substrate temperature (300 °C). The resulting nc-TiC/a-SiC films performed well as electrical contact material. These films' electrical-contact resistance against Ag was remarkably low, 6 µ at a contact force of 800 N compared to 3.2 µ for Ag against Ag. The chemical stability of the nc-TiC/a-SiC films was excellent, as shown by a Battelle flowing mixed corrosive-gas test, with no N, Cl, or S contaminants entering the bulk of the films.
11.	Ekström, Erik, 1989-, et al. (författare) Epitaxial Growth of CaMnO3-y Films on LaAlO3 (112 over bar 0) by Pulsed Direct Current Reactive Magnetron Sputtering 2022 Ingår i: Physica Status Solidi. Rapid Research Letters. - : Wiley-V C H Verlag GMBH. - 1862-6254 .- 1862-6270. ; 16:4 Tidskriftsartikel (refereegranskat)abstract CaMnO3 is a perovskite with attractive magnetic and thermoelectric properties. CaMnO3 films are usually grown by pulsed laser deposition or radio frequency magnetron sputtering from ceramic targets. Herein, epitaxial growth of CaMnO3-y (002) films on a (112 over bar 0)-oriented LaAlO3 substrate using pulsed direct current reactive magnetron sputtering is demonstrated, which is more suitable for industrial scale depositions. The CaMnO3-y shows growth with a small in-plane tilt of <approximate to 0.2 degrees toward the (200) plane of CaMnO3-y and the (1 over bar 104) with respect to the LaAlO3 (112 over bar 0) substrate. X-ray photoelectron spectroscopy of the electronic core levels shows an oxygen deficiency described by CaMnO2.58 that yields a lower Seebeck coefficient and a higher electrical resistivity when compared to stoichiometric CaMnO3. The LaAlO3 (112 over bar 0) substrate promotes tensile-strained growth of single crystals. Scanning transmission electron microscopy and electron energy loss spectroscopy reveal antiphase boundaries composed of Ca on Mn sites along and , forming stacking faults.
12.	Ekström, Erik, et al. (författare) Microstructure control and property switching in stress-free van der Waals epitaxial VO2 films on mica 2023 Ingår i: Materials & design. - : ELSEVIER SCI LTD. - 0264-1275 .- 1873-4197. ; 229 Tidskriftsartikel (refereegranskat)abstract Realizing stress-free inorganic epitaxial films on weakly bonding substrates is of importance for applications that require film transfer onto surfaces that do not seed epitaxy. Film-substrate bonding is usually weakened by harnessing natural van der Waals layers (e.g., graphene) on substrate surfaces, but this is difficult to achieve in non-layered materials. Here, we demonstrate van der Waals epitaxy of stress-free films of a non-layered material VO2 on mica. The films exhibit out-of-plane 010 texture with three inplane orientations inherited from the crystallographic domains of the substrate. The lattice parameters are invariant with film thickness, indicating weak film-substrate bonding and complete interfacial stress relaxation. The out-of-plane domain size scales monotonically with film thickness, but the in-plane domain size exhibits a minimum, indicating that the nucleation of large in-plane domains supports subsequent island growth. Complementary ab initio investigations suggest that VO2 nucleation and van der Waals epitaxy involves subtle polarization effects around, and the active participation of, surface potassium atoms on the mica surface. The VO2 films show a narrow domain-size-sensitive electrical-conductiv ity-temperature hysteresis. These results offer promise for tuning the properties of stress-free van der Waals epitaxial films of non-layered materials such as VO2 through microstructure control (C) 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
13.	Ekström, Erik, et al. (författare) The effects of microstructure, Nb content and secondary Ruddlesden-Popper phase on thermoelectric properties in perovskite CaMn1-xNbxO3 (x=0-0.10) thin films 2020 Ingår i: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 10:13, s. 7918-7926 Tidskriftsartikel (refereegranskat)abstract CaMn1-xNbxO3 (x = 0, 0.5, 0.6, 0.7 and 0.10) thin films have been grown by a two-step sputtering/annealing method. First, rock-salt-structured (Ca,Mn1-x,Nb-x)O thin films were deposited on 11 & x304;00 sapphire using reactive RF magnetron co-sputtering from elemental targets of Ca, Mn and Nb. The CaMn1-xNbxO3 films were then obtained by thermally induced phase transformation from rock-salt-structured (Ca,Mn1-xNbx)O to orthorhombic during post-deposition annealing at 700 degrees C for 3 h in oxygen flow. The X-ray diffraction patterns of pure CaMnO3 showed mixed orientation, while Nb-containing films were epitaxially grown in [101] out of-plane-direction. Scanning transmission electron microscopy showed a Ruddlesden-Popper (R-P) secondary phase in the films, which results in reduction of the electrical and thermal conductivity of CaMn1-xNbxO3. The electrical resistivity and Seebeck coefficient of the pure CaMnO3 film were measured to 2.7 omega cm and -270 mu V K-1 at room temperature, respectively. The electrical resistivity and Seebeck coefficient were reduced by alloying with Nb and was measured to 0.09 omega cm and -145 mu V K-1 for x = 0.05. Yielding a power factor of 21.5 mu W K-2 m(-1) near room temperature, nearly eight times higher than for pure CaMnO3 (2.8 mu W K-2 m(-1)). The power factors for alloyed samples are low compared to other studies on phase-pure material. This is due to high electrical resistivity originating from the secondary R-P phase. The thermal conductivity of the CaMn1-xNbxO3 films is low for all samples and is the lowest for x = 0.07 and 0.10, determined to 1.6 W m(-1) K-1. The low thermal conductivity is attributed to grain boundary scattering and the secondary R-P phase.
14.	Frodelius, Jenny, et al. (författare) Direct current magnetron sputtering from a Ti2AlC target Annan publikation (övrigt vetenskapligt/konstnärligt)
15.	Frodelius, Jenny, et al. (författare) Sputter deposition from a Ti2AlC target: Process characterization and conditions for growth of Ti2AlC 2010 Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 518:6, s. 1621-1626 Tidskriftsartikel (refereegranskat)abstract Sputter deposition from a Ti2AlC target was found to yield Ti-Al-C films with a composition that deviates from the target composition of 2:1:1. For increasing substrate temperature from ambient to 1000 degrees C, the Al content decreased from 22 at.% to 5 at.%, due to re-evaporation. The C content in as-deposited films was equal to or higher than the Ti content. Mass spectrometry of the plasma revealed that the Ti and Al species were essentially thermalized, while a large fraction of C with energies andgt;4 eV was detected. Co-sputtering with Ti yielded a film stoichiometry of 2:0.8:0.9 for Ti:Al:C, which enabled growth of Ti2AlC. These results indicate that an additional Ti flux balances the excess C and therefore provides for more stoichiometric Ti2AlC synthesis conditions.
16.	Gangaprasad Rao, Smita, et al. (författare) Phase formation in CrFeCoNi nitride thin films 2023 Ingår i: Physical Review Materials. - : AMER PHYSICAL SOC. - 2475-9953. ; 7:4 Tidskriftsartikel (refereegranskat)abstract As a single-phase alloy, CrFeCoNi is a face centered cubic (fcc) material related to the archetypical highentropy Cantor alloy CrFeCoNiMn. For thin films, CrFeCoNi of approximately equimolar composition tends to assume an fcc structure when grown at room temperature by magnetron sputtering. However, the single-phase solid solution state is typically not achieved for thin films grown at higher temperatures. The same holds true for Cantor alloy-based ceramics (nitrides and oxides), where phase formation is extremely sensitive to process parameters such as the amount of reactive gas. This study combines theoretical and experimental methods to understand the phase formation in nitrogen-containing CrFeCoNi thin films. Density functional theory calculations considering three competing phases (CrN, Fe-Ni and Co) show that the free energy of mixing, Delta G of (CrFeCoNi)(1-x)N-x solid solutions has a maximum at x = 0.20-0.25, and AG becomes lower when x < 0.20 and x > 0.25. Thin films of (CrFeCoNi)1-xNx (0.14 >= x <= 0.41) grown by magnetron sputtering show stabilization of the metallic fcc when x <= 0.22 and the stabilization of the NaCl B1 structure when x > 0.33, consistent with the theoretical prediction. In contrast, films with intermediate amounts of nitrogen (x = 0.22) grown at higher temperatures show segregation into multiple phases of CrN, Fe-Ni-rich and Co. These results offer an explanation for the requirement of kinetically limited growth conditions at low temperature for obtaining single-phase CrFeCoNi Cantor-like nitrogen-containing thin films and are of importance for understanding the phase-formation mechanisms in multicomponent ceramics. The results from the study further aid in making correlations between the observed mechanical properties and the crystal structure of the films.
17.	Halim, Joseph, et al. (författare) Electronic and optical characterization of 2D Ti2C and Nb2C (MXene) thin films 2019 Ingår i: Journal of Physics. - : IOP PUBLISHING LTD. - 0953-8984 .- 1361-648X. ; 31:16 Tidskriftsartikel (refereegranskat)abstract Two-dimensional (2D) transition metal carbides and/or nitrides (MXenes) are a new class of 2D materials, with extensive opportunities for property tailoring due to the numerous possibilities for varying chemistries and surface terminations. Here, Ti2AlC and Nb2AlC MAX phase epitaxial thin films were deposited on sapphire substrates by physical vapor deposition. The films were then etched in LiF/HCl solutions, yielding Li-intercalated, 2D Ti2CTz and Nb2CTz films, whose terminations, transport and optical properties were characterized. The former exhibits metallic conductivity, with weak localization below 50 K. In contrast, the Nb-based film exhibits an increase in resistivity with decreasing temperature from RT down to 40K consistent with variable range hopping transport. The optical properties of both films were determined from spectroscopic ellipsometry in the 0.75 to 3.50 eV range. The results for Ti2Clz films confirm the metallic behavior. In contrast, no evidence of metallic behavior is observed for the Nb2CT(z) film. The present work therefore demonstrates that one fruitful approach to alter the electronic and optical properties of MXenes is to change the nature of the transition metal.
18.	Halim, Joseph, et al. (författare) Sodium hydroxide and vacuum annealing modifications of the surface terminations of a Ti3C2 (MXene) epitaxial thin film 2018 Ingår i: RSC Advances. - : ROYAL SOC CHEMISTRY. - 2046-2069. ; 8:64, s. 36785-36790 Tidskriftsartikel (refereegranskat)abstract We investigate, and quantify, changes in structure and surface terminations of epitaxial thin films of titanium carbide (Ti3C2) MXene, when treated by sodium hydroxide solution followed by vacuum annealing at 550 degrees C. Using X-ray photoelectron spectroscopy and scanning transmission electron microscopy, we show that NaOH treatment produce an increase in the c-lattice parameter together with an increase in the O terminations and a decrease in the F terminations. There is also an increase in the percentage of the binding energy of Ti-species in Ti 2p XPS region, which suggests an increase in the overall oxidation state of Ti. After subsequent annealing, the c-lattice parameter is slightly reduced, the overall oxidation state of Ti is decreased, and the F surface terminations are further diminished, leaving a surface with predominantly O as the surface terminating species. It is important to note that NaOH treatment facilitates removal of F at lower annealing temperatures than previously reported, which in turn is important for the range of attainable properties.
19.	Halim, Joseph, 1985-, et al. (författare) Synthesis of Two-Dimensional Nb1.33C (MXene) with Randomly Distributed Vacancies by Etching of the Quaternary Solid Solution (Nb2/3Sc1/3)2AlC MAX Phase 2018 Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; 1:6, s. 2455-2460 Tidskriftsartikel (refereegranskat)abstract Introducing point defects in two-dimensional (2D) materials can alter or enhance their properties. Here, we demonstrate how etching a laminated (Nb2/3Sc1/3)2AlC MAX phase (solid solution) of both the Sc and Al atoms results in a 2D Nb1.33C material (MXene) with a large number of vacancies and vacancy clusters. This method is applicable to any quaternary, or higher, MAX phase, wherein one of the transition metals is more reactive than the other and could be of vital importance in applications such as catalysis and energy storage. We also report, for the first time, on the existence of solid solution (Nb2/3Sc1/3)3AlC2 and (Nb2/3Sc1/3)4AlC3 phases.
20.	Hallberg, Per, 1965- (författare) Applanation Resonance Tonometry for Intraocular Pressure Measurement 2006 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Elevated intraocular pressure (IOP) is one of the major risk factors for glaucoma. Since glaucoma is a leading cause of blindness, reliable methods for measuring the IOP are important. This doctoral dissertation presents a new method, applanation resonance tonometry (ART), for measurement of IOP. The method is based on resonance sensor technology combined with the novel multipoint analysis of continuously sampled data of both contact force and contact area. The ART was evaluated in in vitro porcine-eye studies as well as in clinic on both healthy volunteers and patients. A new symmetric probe with a larger sensor tip and improved aligning light was developed and evaluated in vitro. It showed that the error from off-centring was highly reduced. The new ART probe, used as a biomicroscope device (ARTBiom) and as a handheld device (ARTHand), was further evaluated in a clinical study designed in accordance with the International Standard Organisation’s (ISO) requirement. Both the ARTBiom and the ARTHand met the precision set by the requirements. Laser surgery is a common way to correct vision. The biomechanical effect of photorefractive keratectomy (PRK) on IOP measurements was evaluated using Goldmann applanation tonometry (GAT) and ART in an in vitro study. Both methods were affected, but to a different extent. The flat contact probe of GAT, as compared with the convex tip of ART, and single point vs. multipoint approach, provide explanation to the ART advantage regarding measurement error of IOP after PRK. In conclusion, resonance sensor technology has made it possible to introduce a new multipoint method for measuring IOP, and the method is relevant for measuring IOP in humans. It may be possible to reduce errors in the clinical measurement of IOP with this new method, especially after corneal surgery. The ART has the potential to become a useful clinical instrument for IOP measurement.
21.	Hedström, Brita, et al. (författare) Visby Innerstad : En användningsplan 1973 Rapport (populärvet., debatt m.m.)abstract Sedan lång tid föreligger i stort sett enighet om att bevara innerstadens bebyggelse och att anpassa eventuella nytillskott till det redan bestående. Med den inställningen har förändringsprocessen både dämpats och mildrats men ändå inte bragts att avstanna. Förändringar sker ständigt om det också huvudsakligen i smått: de många synbart så anspråkslösa byggnadsåtgärderna adderar efterhand ihop sig till något större och mer genomgripande. Långsamt, nästan omärkligt, ändrar innerstaden sitt ansikte.Ändå är det inte själva husen som förändrats mest utan användningen av dem. Ur funktionell synpunkt har 1950 - och 60-talen har varit något av en omstörtning i innerstadens historia: den har förlorat nästan hälften av de boende, en stor del av detaljhandeln och praktiskt taget helt sin gamla roll som skolcentrum. I gengäld har ytterstaden vuxit ut till ett sammanhängande kilometerbrett bälte. Till stor del av denna funktionella förändring en följd av beslutet att bevara innerstadens bebyggelse. Vad som inte fått plats inom den gamla ramen har etablerats utandör den.Föreliggande arbete vill ge en översiktlig bild av förändringsförloppen, sedda i ett långt tidsperspektiv men med tonvikt på dagsläget. Bebyggelsen tas upp till utförlig granskning men också användningen av den. Det är just samspelet mellan husen och de funtkioner, de fyller, som kan sägas utgöra bokens huvudtema. I de flesta fall är detta sammanhang hus-användning alldeles konfliktfritt och föranleder därför inte heller någon diskussion. Vad som behandlas är de relativt få problematiska fallen, hus som borde rustas upp för att fylla sin uppgift, hus som är olämpligt nyttjade eller inte använda alls. En serie sådana fall tas upp till systematisk genomgång; samtidigt berörs också de trafik - och miljömässiga konsekvenserna. Bokens syfte är alltså klart: den ger ett underlag av fakta för arbetet med att jämka samman byggnader och användningsformer. I den meningen kan skriften kallas en anvädningsplan för Visby innanför murarna.Arkitekturskolanas arbete har bedrivitis parallellt med den kommunala Innerstadskommitténs verksamhet. Något organiserat samarbete har inte förekommit med de informella kontakterna har varit både täta och goda. Att likheterna mellan Innerstadskommittén och Arkitekturskolans slutsatser blivit så pass stora, kan tillskrivas en gemensam helhetssyn.En av Arkitekturskolans elever, arkitekt Lars-Ingvar Larsson, har tidigare självständigt genomfört en undersökning av förändringar i innerstaden 1945-70- Denna studie publicerats separat och bör uppfattas som ett komplement till den hör föreliggande.Förutom de i innehållsförteckningen nämnda har ytterligare några aktivt medverkat i arbetet. Studiet av trafikfrågorna i innerstaden, i hamnen och öster om ringmuren leddes av Åke Claesson, I fältstudier och diskussioner medverkande Göran Månsson.Arkitekturskolan har fått god hjälp av ett antal initierade personer i Visby. Särskild tacksamhet är vi skyldiga byggnadsnämnden ordförande Henning Jacobson, kommunalrådet C B Stenström, stadsarkitekten Måns Hagbergm f. länsbostadsdorektören Åke Malmberg och landsantikvarien Gunnar Svahnström. I boken publiceringskostnaderna har ekonomiskt bidrag lämnats av Gotlands kommun och Riksantikvarieämbetet.Boken har redigerats av Sture Balgård och Ann Mari Westerlind med hjälp av Henrik O Andersson, Bo Ek, Göran Lindahl, Fredrik von Platen, John Sjöström Gunnar Westerlind och Hans Wetterfors.Skeppsholmen, Stockholm, sommaren 1973.Arkitekturskolans lärare och elever.
22.	Khatibi, Ali, et al. (författare) Face-Centered Cubic (Al1-xCrx)2O3 2011 Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 519:8, s. 2426-2429 Tidskriftsartikel (refereegranskat)abstract We report the discovery of a face-centered cubic (Al1−xCrx)2O3 solid solution [0.60bxb0.70] in films grownonto Si substrates using reactive radio frequency magnetron sputtering from Al and Cr targets at 400 °C. Theproposed structure is NaCl-like with 33% vacancies on the metal sites. The unit cell parameter is 4.04 Å asdetermined by X-ray diffraction. The films have a b100N preferred crystallographic orientation and exhibithardness values up to 26 GPa and an elastic modulus of 220–235 GPa.
23.	Lai, Chung-Chuan, et al. (författare) Phase formation of nanolaminated Mo2AuC and Mo-2(Au1-xGax)(2)C by a substitutional reaction within Au-capped Mo2GaC and Mo2Ga2C thin films 2017 Ingår i: Nanoscale. - : ROYAL SOC CHEMISTRY. - 2040-3364 .- 2040-3372. ; 9:45, s. 17681-17687 Tidskriftsartikel (refereegranskat)abstract Au-containing nanolaminated carbides Mo2AuC and Mo-2(Au1-xGax)(2)C were synthesized by a thermally induced substitutional reaction in Mo2GaC and Mo2Ga2C, respectively. The Au substitution of the Ga layers in the structures was observed using cross-sectional high-resolution scanning transmission electron microscopy. Expansion of c lattice parameters was also observed in the Au-containing phases compared to the original phases. Energy dispersive spectroscopy detected residual Ga in Au-substituted layers of both phases with a peculiar Ga in-plane ordering for Au : Ga = 9 : 1 ratio along the Au-Ga layers in Mo-2(Au1-xGax)(2)C. These results indicate a generalization of the Au substitution reaction for the A elements in MAX phases.
24.	Le Febvrier, Arnaud, et al. (författare) An upgraded ultra-high vacuum magnetron-sputtering system for high-versatility and software-controlled deposition 2021 Ingår i: Vacuum. - : Pergamon-Elsevier Science Ltd. - 0042-207X .- 1879-2715. ; 187 Tidskriftsartikel (refereegranskat)abstract Magnetron sputtering is a widely used physical vapor deposition technique. Reactive sputtering is used for the deposition of, e.g, oxides, nitrides and carbides. In fundamental research, versatility is essential when designing or upgrading a deposition chamber. Furthermore, automated deposition systems are the norm in industrial production, but relatively uncommon in laboratory-scale systems used primarily for fundamental research. Combining automatization and computerized control with the required versatility for fundamental research constitutes a challenge in designing, developing, and upgrading laboratory deposition systems. The present article provides a detailed description of the design of a lab-scale deposition chamber for magnetron sputtering used for the deposition of metallic, oxide, nitride and oxynitride films with automated controls, dc or pulsed bias, and combined with a coil to enhance the plasma density near the substrate. LabVIEW software (provided as Supplementary Information) has been developed for a high degree of computerized or automated control of hardware and processes control and logging of process details.
25.	Li, Mian, et al. (författare) Element Replacement Approach by Reaction with Lewis Acidic Molten Salts to Synthesize Nanolaminated MAX Phases and MXenes 2019 Ingår i: Journal of the American Chemical Society. - : AMER CHEMICAL SOC. - 0002-7863 .- 1520-5126. ; 141:11, s. 4730-4737 Tidskriftsartikel (refereegranskat)abstract Nanolaminated materials are important because of their exceptional properties and wide range of applications. Here, we demonstrate a general approach to synthesizing a series of Zn-based MAX phases and Cl-terminated MXenes originating from the replacement reaction between the MAX phase and the late transition-metal halides. The approach is a top-down route that enables the late transitional element atom (Zn in the present case) to occupy the A site in the pre-existing MAX phase structure. Using this replacement reaction between the Zn element from molten ZnCl2 and the Al element in MAX phase precursors (Ti3AlC2, Ti2AlC, Ti2AlN, and V2AlC), novel MAX phases Ti3ZnC2, Ti2ZnC, Ti2ZnN, and V2ZnC were synthesized. When employing excess ZnCl2, Cl-terminated MXenes (such as Ti3C2Cl2 and Ti2CCl2) were derived by a subsequent exfoliation of Ti3ZnC2 and Ti2ZnC due to the strong Lewis acidity of molten ZnCl2. These results indicate that A-site element replacement in traditional MAX phases by late transition-metal halides opens the door to explore MAX phases that are not thermodynamically stable at high temperature and would be difficult to synthesize through the commonly employed powder metallurgy approach. In addition, this is the first time that exclusively Cl-terminated MXenes were obtained, and the etching effect of Lewis acid in molten salts provides a green and viable route to preparing MXenes through an HF-free chemical approach.
26.	Li, Mian, et al. (författare) Halogenated Ti3C2 MXenes with Electrochemically Active Terminals for High-Performance Zinc Ion Batteries 2021 Ingår i: ACS Nano. - : AMER CHEMICAL SOC. - 1936-0851 .- 1936-086X. ; 15:1, s. 1077-1085 Tidskriftsartikel (refereegranskat)abstract The class of two-dimensional metal carbides and nitrides known as MXenes offer a distinct manner of property tailoring for a wide range of applications. The ability to tune the surface chemistry for expanding the property space of MXenes is thus an important topic, although experimental exploration of surface terminals remains a challenge. Here, we synthesized Ti3C2 MXene with unitary, binary, and ternary halogen terminals, e.g., -Cl, -Br, -I, -BrI, and -ClBrI, to investigate the effect of surface chemistry on the properties of MXenes. The electrochemical activity of Br and I elements results in the extraordinary electrochemical performance of the MXenes as cathodes for aqueous zinc ion batteries. The -Br- and -I-containing MXenes, e.g., Ti3C2Br2 and Ti3C2I2, exhibit distinct discharge platforms with considerable capacities of 97.6 and 135 mA.g(-1). Ti3C2 (BrI) and Ti3C2 (ClBrI) exhibit dual discharge platforms with capacities of 117.2 and 106.7 mAh.g(-1). In contrast, the previously discovered MXenes Ti3C2Cl2 and Ti3C2 (OF) exhibit no discharge platforms and only similar to 50% of capacities and energy densities of Ti3C2Br2. These results emphasize the effectiveness of the Lewis-acidic-melt etching route for tuning the surface chemistry of MXenes and also show promise for expanding the MXene family toward various applications.
27.	Li, Youbing, et al. (författare) A general Lewis acidic etching route for preparing MXenes with enhanced electrochemical performance in non-aqueous electrolyte 2020 Ingår i: Nature Materials. - : NATURE PUBLISHING GROUP. - 1476-1122 .- 1476-4660. ; 19:8, s. 894-899 Tidskriftsartikel (refereegranskat)abstract Two-dimensional transition metal carbides and nitrides, known as MXenes, are currently considered as energy storage materials. A generic Lewis acidic etching route for preparing high-rate negative-electrode MXenes with enhanced electrochemical performance in non-aqueous electrolyte is now proposed. Two-dimensional carbides and nitrides of transition metals, known as MXenes, are a fast-growing family of materials that have attracted attention as energy storage materials. MXenes are mainly prepared from Al-containing MAX phases (where A = Al) by Al dissolution in F-containing solution; most other MAX phases have not been explored. Here a redox-controlled A-site etching of MAX phases in Lewis acidic melts is proposed and validated by the synthesis of various MXenes from unconventional MAX-phase precursors with A elements Si, Zn and Ga. A negative electrode of Ti3C2 MXene material obtained through this molten salt synthesis method delivers a Li+ storage capacity of up to 738 C g(-1) (205 mAh g(-1)) with high charge-discharge rate and a pseudocapacitive-like electrochemical signature in 1 M LiPF6 carbonate-based electrolyte. MXenes prepared via this molten salt synthesis route may prove suitable for use as high-rate negative-electrode materials for electrochemical energy storage applications.
28.	Li, Youbing, et al. (författare) A-site alloying-guided universal design of noble metal-based MAX phases 2024 Ingår i: Matter. - : Cell Press. - 2590-2393 .- 2590-2385. ; 7:2, s. 523-538 Tidskriftsartikel (refereegranskat)abstract Mn+1AXn (MAX) phases have attracted significant attention due to their structural diversity and potential applications. Designing MAX phases with single-atom-thick A layers featuring 4d/5d-orbital electronic elements is interesting work. Here, we present a comprehensive report on noble metal-based M2(A1-xA′x)C (M = V, Ti, Nb; A = Al, Sn, In, Ga, Ge; A′ = Ru, Rh, Pd, Ir, Pt, Au and combinations thereof; 0 < x ≤ 0.4) phases featuring A sublayers of 4d/5d-orbital electronic elements through an A-site alloying strategy. The chemical composition of MAX phases can be adjusted by selecting different M- and A-site elements, with morphology tailored by distinct C sources. Furthermore, the V2(Sn0.8Pt0.2)C (15.7 wt % Pt) catalyst showed better performance for hydrogen evolution reaction compared to the commercial Pt/C (20 wt % Pt) electrode. This study highlights the prospects of A-site alloying for the design of novel MAX phases with unique properties and promising applications in electrocatalysis and beyond.
29.	Li, Youbing, et al. (författare) Electrochemical Lithium Storage Performance of Molten Salt Derived V2SnC MAX Phase 2021 Ingår i: Nano-Micro Letters. - : Springer. - 2311-6706 .- 2150-5551. ; 13:1 Tidskriftsartikel (refereegranskat)abstract MAX phases are gaining attention as precursors of two-dimensional MXenes that are intensively pursued in applications for electrochemical energy storage. Here, we report the preparation of V2SnC MAX phase by the molten salt method. V2SnC is investigated as a lithium storage anode, showing a high gravimetric capacity of 490 mAh g(-1) and volumetric capacity of 570 mAh cm(-3) as well as superior rate performance of 95 mAh g(-1) (110 mAh cm(-3)) at 50 C, surpassing the ever-reported performance of MAX phase anodes. Supported by operando X-ray diffraction and density functional theory, a charge storage mechanism with dual redox reaction is proposed with a Sn-Li (de)alloying reaction that occurs at the edge sites of V2SnC particles where Sn atoms are exposed to the electrolyte followed by a redox reaction that occurs at V2C layers with Li. This study offers promise of using MAX phases with M-site and A-site elements that are redox active as high-rate lithium storage materials.
30.	Li, Youbing, et al. (författare) Multielemental single atom-thick A layers in nanolaminated V2(Sn, A) C (A = Fe, Co, Ni, Mn) for tailoring magnetic properties 2020 Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : NATL ACAD SCIENCES. - 0027-8424 .- 1091-6490. ; 117:2, s. 820-825 Tidskriftsartikel (refereegranskat)abstract Tailoring of individual single-atom-thick layers in nanolaminated materials offers atomic-level control over material properties. Nonetheless, multielement alloying in individual atomic layers in nanolaminates is largely unexplored. Here, we report 15 inherently nanolaminated V-2(A(x)Sn(1-x))C (A = Fe, Co, Ni, Mn, and combinations thereof, with x similar to 1/3) MAX phases synthesized by an alloy-guided reaction. The simultaneous occupancy of the 4 magnetic elements and Sn in the individual single-atom-thick A layers constitutes high-entropy MAX phase in which multielemental alloying exclusively occurs in the 2 -dimensional (2D) A layers. V-2(A(x)Sn(1-x))C exhibit distinct ferromagnetic behavior that can be compositionally tailored from the multielement A-layer alloying. Density functional theory and phase diagram calculations are performed to understand the structure stability of these MAX phases. This 2D multielemental alloying approach provides a structural design route to discover nanolaminated materials and expand their chemical and physical properties. In fact, the magnetic behavior of these multielemental MAX phases shows strong dependency on the combination of various elements.
31.	Li, Youbing, et al. (författare) Nanolaminated Ternary Transition Metal Carbide (MAX Phase)-Derived Core-Shell Structure Electrocatalysts for Hydrogen Evolution and Oxygen Evolution Reactions in Alkaline Electrolytes 2023 Ingår i: The Journal of Physical Chemistry Letters. - : AMER CHEMICAL SOC. - 1948-7185. ; 14:2, s. 481-488 Tidskriftsartikel (refereegranskat)abstract The development of abundant, cheap, and highly active catalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is important for hydrogen production. Nanolaminate ternary transition metal carbides (MAX phases) and their derived two-dimensional transition metal carbides (MXenes) have attracted considerable interest for electrocatalyst applications. Herein, four new MAX@MXene core-shell structures (Ta2CoC@ Ta2CTx, Ta2NiC@Ta2CTx, Nb2CoC@Nb2CTx, and Nb2NiC@Nb2CTx), in which the core region is Co/Ni-MAX phases while the edge region is MXenes, have been prepared. Under alkaline electrolyte conditions, the Ta2CoC@Ta2CTx core-shell structure showed an overpotential of 239 mV and excellent stability during the HER with MXenes as the active sites. For the OER, the Ta2CoC@Ta2CTx core- shell structure showed an overpotential of 373 mV and a small Tafel plot (56 mV dec-1), which maintained a bulk crystalline structure and generated Co-based oxyhydroxides that formed by surface reconstruction as active sites. Considering rich chemical compositions and structures of MAX phases, this work provides a new strategy for designing multifunctional electrocatalysts and also paves the way for further development of MAX phase-based materials for clean energy applications.
32.	Li, Youbing, et al. (författare) Near-room temperature ferromagnetic behavior of single-atom-thick 2D iron in nanolaminated ternary MAX phases 2021 Ingår i: Applied Physics Reviews. - : AIP Publishing. - 1931-9401. ; 8:3 Tidskriftsartikel (refereegranskat)abstract M(n+)(1)AX(n) (MAX) phases nanolaminated ternary carbides or nitrides possess a unique crystal structure in which single-atom-thick "A" sublayers are interleaved by alternative stacking of a "Mn+1Xn" sublayer; these materials have been investigated as promising high-safety structural materials for industrial applications because of their laminated structure and metal and ceramic properties. However, limited of A-site elements in the definition of M(n+)(1)AX(n) phases, it is a huge challenge for designing nanolaminated ferromagnetic materials with single-atom-thick two-dimensional iron layers occupying the A layers in the M(n+)(1)AX(n) phases. Here, we report three new ternary magnetic M(n+)(1)AX(n) phases (Ta2FeC, Ti2FeN, and Nb2FeC) with A sublayers of single-atom-thick two-dimensional iron through an isomorphous replacement reaction of M(n+)(1)AX(n) precursors (Ta2AlC, Ti2AlN, and Nb2AlC) with a Lewis acid salts (FeCl2). All these M(n+)(1)AX(n) phases exhibit ferromagnetic behavior. The Curie temperatures of the Ta2FeC and Nb2FeC M(n+)(1)AX(n) phases are 281 and 291K, respectively, i.e., close to room temperature. The saturation magnetization of these ternary magnetic MAX phases is almost two orders of magnitude higher than V-2(Sn,Fe)C, whose A-site is partially substituted by Fe. Theoretical calculations on magnetic orderings of spin moments of Fe atoms in these nanolaminated magnetic M(n+)(1)AX(n) phases reveal that the magnetism can be mainly ascribed to an intralayer exchange interaction of the two-dimensional Fe atomic layers. Owing to the richness in composition of M(n+)(1)AX(n) phases, our work provides a large imaginary space for constructing functional single-atom-thick two-dimensional layers in materials using these nanolaminated templates.
33.	Li, Youbing, et al. (författare) Single-Atom-Thick Active Layers Realized in Nanolaminated Ti-3(AlxCu1-x)C-2 and Its Artificial Enzyme Behavior 2019 Ingår i: ACS Nano. - : AMER CHEMICAL SOC. - 1936-0851 .- 1936-086X. ; 13:8, s. 9198-9205 Tidskriftsartikel (refereegranskat)abstract A Ti-3(AlxCu1-x)C-2 phase with Cu atoms with a degree of ordering in the A plane is synthesized through the A site replacement reaction in CuCl2 molten salt. The weakly bonded single -atom -thick Cu layers in a Ti-3(AlxCu1-x)C-2 MAX phase provide actives sites for catalysis chemistry. As -synthesized Ti-3(AlxCu1-x)C-2 presents unusual peroxidase-like catalytic activity similar to that of natural enzymes. A fabricated Ti-3(AlxCu1-x)C-2/chitosan/glassy carbon electrode biosensor prototype also exhibits a low detection limit in the electrochemical sensing of H2O2. These results have broad implications for property tailoring in a nanolaminated MAX phase by replacing the A site with late transition elements.
34.	Locke, Adam E, et al. (författare) Genetic studies of body mass index yield new insights for obesity biology. 2015 Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 518:7538, s. 197-401 Tidskriftsartikel (refereegranskat)abstract Obesity is heritable and predisposes to many diseases. To understand the genetic basis of obesity better, here we conduct a genome-wide association study and Metabochip meta-analysis of body mass index (BMI), a measure commonly used to define obesity and assess adiposity, in up to 339,224 individuals. This analysis identifies 97 BMI-associated loci (P < 5 × 10(-8)), 56 of which are novel. Five loci demonstrate clear evidence of several independent association signals, and many loci have significant effects on other metabolic phenotypes. The 97 loci account for ∼2.7% of BMI variation, and genome-wide estimates suggest that common variation accounts for >20% of BMI variation. Pathway analyses provide strong support for a role of the central nervous system in obesity susceptibility and implicate new genes and pathways, including those related to synaptic function, glutamate signalling, insulin secretion/action, energy metabolism, lipid biology and adipogenesis.
35.	Lu, Jun, 1962-, et al. (författare) Tin+1Cn MXenes with fully saturated and thermally stable Cl terminations 2019 Ingår i: Nanoscale Advances. - : Royal Society of Chemistry. - 2516-0230. ; 1:9, s. 3680-3685 Tidskriftsartikel (refereegranskat)abstract MXenes are a rapidly growing family of 2D materials that exhibit a highly versatile structure and composition, allowing for significant tuning of the materials properties. These properties are, however, ultimately limited by the surface terminations, which are typically a mixture of species, including F and O that are inherent to the MXene processing. Other and robust terminations are lacking. Here, we apply high-resolution scanning transmission electron microscopy (STEM), corresponding image simulations and first-principles calculations to investigate the surface terminations on MXenes synthesized from MAX phases through Lewis acidic melts. The results show that atomic Cl terminates the synthesized MXenes, with mere residual presence of other termination species. Furthermore, in situ STEM-electron energy loss spectroscopy (EELS) heating experiments show that the Cl terminations are stable up to 750 degrees C. Thus, we present an attractive new termination that widely expands the MXenes functionalization space and enables new applications.
36.	Ma, Hairui, et al. (författare) Effect of modulation period and thickness ratio on the growth and mechanical properties of heteroepitaxial c-Ti0.4Al0.6N/h-Cr2N multilayer films 2023 Ingår i: Surface & Coatings Technology. - : ELSEVIER SCIENCE SA. - 0257-8972 .- 1879-3347. ; 472 Tidskriftsartikel (refereegranskat)abstract c-TiAlN/h-Cr2N multilayer thin films, with modulation period lambda of 10 nm, 20 nm, and 30 nm and different Cr2N/lambda thickness ratios (25 %, 50 % and 75 %), were deposited on c-plane sapphire using reactive DC magnetron sputtering. All multilayers exhibited preferred orientation [Cr2N(0001)/ TiAlN(111)](x), regardless of the modulation period and thickness ratios. X-ray diffraction f-scans revealed an influence of the Cr2N layer thickness on the overall orientation quality of the multilayer, where the thicker the Cr2N layer the higher orientation quality. Atomically resolved high-angle annular dark-field scanning transmission electron microscopy revealed well defined and homogeneous atom stacking in the Cr2N layers. In contrast, the cubic TiAlN layer was found to be composed of coherent cubic AlN-rich and TiN-rich regions. Additionally, the TiAlN layers were found with a higher density of grain boundaries compared to the Cr2N layers. Mechanical properties evaluation revealed that the film with a 20 nm period and 75 % Cr2N thickness ratio exhibited the highest hardness of 27.11 +/- 0.72 GPa and an reduced elastic modulus of 349.1 +/- 6.84 GPa. The hardness increased as the thickness of Cr2N increased, until reaching 10 nm, after which it remained at a high level (similar to 25 GPa).
37.	Mian, Li, et al. (författare) Synthesis of Novel MAX Phase Ti3ZnC2 via A-site-element-substitution Approach 2019 Ingår i: Journal of Inorganic Materials. - : SCIENCE PRESS. - 1000-324X. ; 34:1, s. 60-64 Tidskriftsartikel (refereegranskat)abstract Using Ti3AlC2 as the precursor, a new MAX phase Ti3ZnC2 was synthesized via an A-elemental substitution reaction in a molten salts bath. Composition and crystal structure of Ti3ZnC2 were confirmed by XRD, SEM and TEM analysis. Its structure stability and lattice parameter of Ti3ZnC2 were further proved by a theoretical calculation based on density function theory (DFT). Moreover, thermodynamics of A-elemental substitution reactions based on Fe, Co, Ni, and Cu were investigated. All results indicated that the similar substitution reactions are feasible to form series of MAX phases whose A sites are Fe, Co, Ni, and Cu elements. The substitution reaction was achieved by diffusion of Zn atoms into A-layers of Ti3AlC2, which requires Al-Zn eutectic formation at high temperatures. The molten salts provided a moderate environment for substitution reaction and accelerated reaction dynamics. The major advantage of this substitution reaction is that MAX phase keeps individual metal carbide layers intact, thus the formation of competitive phases, such as MA alloys, was avoided. The proposed A-elemental substitution reactions approach opens a new door to design and synthesize novel MAX phases which could not be synthesized by the traditional methods.
38.	Nedfors, Nils, et al. (författare) Superhard NbB2-x thin films deposited by dc magnetron sputtering 2014 Ingår i: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 257, s. 295-300 Tidskriftsartikel (refereegranskat)abstract We have deposited weakly textured substoichiometric NbB2-x thin films by magnetron sputtering from a NbB2 target. The films exhibit superhardness (42 ± 4 GPa), previously only observed in overstoichiometric TiB2 thin films, and explained by a self-organized nanostructuring, where thin TiB2 columnar grains hinder nucleation and slip of dislocations and a B-rich tissue phase between the grains prevent grain-boundary sliding. The wide homogeneity range for the NbB2 phase allows a similar ultra-thin B-rich tissue phase to form between thin (5 – 10 nm) columnar NbB2-x grains also for films with a B/Nb atomic ratio of 1.8, as revealed here by analytical aberration-corrected scanning transmission electron microscopy. Furthermore, a coefficient of friction of 0.16 is measured for a NbB2-x film sliding against stainless steel with a wear rate of 4x10-7 mm3/Nm. X-ray photoelectron spectroscopy results suggest that the low friction is due to the formation of a lubricating boric acid film.
39.	Nilsson, Kerstin, et al. (författare) Vi är oroade över senare ålderspension 2017 Ingår i: Dagens Samhälle. - 1652-6511. Tidskriftsartikel (populärvet., debatt m.m.)abstract Var fjärde person blir i dag sjuk till följd av sitt arbete. Att höja pensionsåldern för alla yrkesgrupper, utan konkreta åtgärder för att minska ohälsan, är därför problematiskt och mycket oroande. Det är, enligt forskarna, inte långsiktigt samhällsekonomiskt lönsamt att utan andra åtgärder höja pensionsåldern för alla. Vi – 54 forskare – är mycket oroade över konsekvenserna av att, som föreslagits, senarelägga ålderspensionen.Förslaget utgår i princip från arbetskraftsdeltagande i princip enbart styrs av ekonomin, medan forskningen visar att det bara är en av flera faktorer som styr hur länge och hur mycket människor väljer att arbeta.Det här sättet att lösa problemet med en åldrande befolkning och ett sviktande pensionssystem är inte samhällsekonomiskt lönsamt på lång sikt, utan riskerar bara att flytta runt folk mellan olika ersättningssystem. Pensionssystemet bygger på att vi ska arbeta en viss del av våra liv för att tjäna in vår pension. Vi bör dock inte enbart utgå ifrån ålder eller antalet år sedan en person föddes då korttidsutbildade generellt träder in på arbetsmarknaden tidigare än långtidsutbildade. De med kortare utbildningstid har alltså varit en del av arbetskraften från en yngre ålder. Människor med kortare utbildning har också oftare ett arbete som innebär påfrestningar som kan inverka negativt på hälsotillståndet och som till och med kan påskynda det biologiska åldrandet. Dessutom lever korttidsutbildade generellt sett inte lika länge som långtidsutbildade, vilket delvis även avspeglar skilda livs- och arbetsvillkor.Ta nytta av den forskning som vi har tagit fram. Ekonomin är självklart viktigt för att vi ska vilja arbeta, men den är som sagt enbart en av flera faktorer med betydelse vårt arbetsliv.Hälsotillståndet, både det fysiska och det mentala, har en avgörande betydelse för hur länge och hur mycket vi orkar arbeta. Ett fysiskt och mentalt belastande arbete är en stark riskfaktor för en nedsatt hälsa i slutet av arbetslivet. Arbetstid, arbetstakt och möjlighet till återhämtning spelar en allt större roll ju äldre vi blir. Andra aspekter är arbetsinnehåll, hur meningsfulla och stimulerande arbetsuppgifterna är, balansen mellan arbete och familjesituation och fritidsaktiviteter. Organisationskultur, ledarskapet, stöd i arbetet och kompetens har stor betydelse för om vi ska kunna och vilja arbeta till en högre ålder. Vi måste ta större hänsyn till olika förutsättningar och varierande funktionsförmåga och utifrån detta anpassa de åtgärder som gör att arbetslivet blir möjligt och hållbart för allt fler även i högre ålder.Ett hållbart och acceptabelt pensionssystem måste därför utformas utifrån personliga förutsättningar och förhållanden i arbetslivet. Ett hållbart arbetsliv för allt fler i vår åldrande befolkning fordrar att vi samtidigt beaktar faktorer som relaterar till biologisk/kroppslig ålder, mental/kognitiv ålder samt social ålder/livsloppsfas samt de attityder som är kopplade till ålder.
40.	Shu, Rui, et al. (författare) Solid-State Janus Nanoprecipitation Enables Amorphous-Like Heat Conduction in Crystalline Mg3Sb2-Based Thermoelectric Materials 2022 Ingår i: Advanced Science. - : Wiley. - 2198-3844. ; 9:25 Tidskriftsartikel (refereegranskat)abstract Solid-state precipitation can be used to tailor material properties, ranging from ferromagnets and catalysts to mechanical strengthening and energy storage. Thermoelectric properties can be modified by precipitation to enhance phonon scattering while retaining charge-carrier transmission. Here, unconventional Janus-type nanoprecipitates are uncovered in Mg3Sb1.5Bi0.5 formed by side-by-side Bi- and Ge-rich appendages, in contrast to separate nanoprecipitate formation. These Janus nanoprecipitates result from local comelting of Bi and Ge during sintering, enabling an amorphous-like lattice thermal conductivity. A precipitate size effect on phonon scattering is observed due to the balance between alloy-disorder and nanoprecipitate scattering. The thermoelectric figure-of-merit ZT reaches 0.6 near room temperature and 1.6 at 773 K. The Janus nanoprecipitation can be introduced into other materials and may act as a general property-tailoring mechanism.
41.	Singh, Niraj Kumar, et al. (författare) Electron-phonon coupling and quantum correction to topological magnetoconductivity in Bi2GeTe4 2022 Ingår i: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 105:4 Tidskriftsartikel (refereegranskat)abstract We report structure, vibrational properties, and weak antilocalization-induced quantum correction to magnetoconductivity in single-crystal Bi2GeTe4. Surface band-structure calculations show a single Dirac cone corresponding to topological surface states in Bi2GeTe4. An estimated phase coherence length, lΦ ~ to 143 nm and prefactor α~-1.54 from Hikami-Larkin-Nagaoka fitting of magnetoconductivity describe the quantum correction to conductivity. An anomalous temperature dependence of A1g Raman modes confirms enhanced electron-phonon interactions. Our results establish that electrons of the topological state can interact with the phonons involving the vibrations of Bi-Te in Bi2GeTe4.
42.	Wang, Ji, et al. (författare) Structural stability under Xe-ion irradiation of TiZrNbTaV-based high-entropy alloy and nitride films 2023 Ingår i: Surface & Coatings Technology. - : ELSEVIER SCIENCE SA. - 0257-8972 .- 1879-3347. ; 454 Tidskriftsartikel (refereegranskat)abstract Refractory high-entropy protective coatings are of interest for nuclear fuel cladding applications due to their corrosion resistant properties and irradiation resistance at elevated temperature. Here, TiZrNbTaV metallic and (TiZrNbTaV)N films were deposited by magnetron co-sputtering. The metal elemental contents of both films were nearly equiatomic. These films were irradiated by Xe ions at room temperature and 500 degrees C, and examined by X-ray diffraction and transmission electron microscopy. The as-deposited (TiZrNbTaV)N film showed a single NaCl-type fcc phase and a pronounced columnar growth structure, which could remain intact after irradiation treatments. In contrast, the as-deposited TiZrNbTaV film exhibited an amorphous structure and formed a bcc phase structure after irradiation at 500 degrees C. The TiZrNbTaV film after irradiation at 500 degrees C composed of depth -dependent size of grains. This distribution of grain size is consistent with simulated displacement damage. The stable structure of (TiZrNbTaV)N film under high temperature irradiation indicates that these materials have potential for use as protective coatings for nuclear fuel claddings.
43.	Wilhelmsson, O., et al. (författare) Deposition and characterization of ternary thin films within the Ti-Al-C system by DC magnetron sputtering 2006 Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248 .- 1873-5002. ; 291:1, s. 290-300 Tidskriftsartikel (refereegranskat)abstract The formation of ternary compounds within the Ti-Al-C system was studied by magnetron sputtering for thin-film deposition and first-principles calculations for phase stability. As-deposited films were characterized with X-ray diffraction (XRD) and high-resolution transmission electron microscopy (TEM). The hardness and Young's moduli of the material were studied by nanoindentation. Epitaxial and phase-pure films of Mn+1AXn phases Ti3AlC2 and Ti2AlC as well as the perovskite phase Ti3AlC were deposited on Al2O3(00l) wafers kept at temperatures between 800 and 900 °C. The only ternary phases observed at low temperatures (300 °C) were Ti3AlC and cubic (Ti,Al)C, the latter can be described as a metastable solid solution of Al in TiC similar to the more studied (Ti,Al)N system. The difficulties to form MAX phases at low substrate temperatures were attributed of requirement for a sufficient diffusivity to partition the elements corresponding to the relatively complex crystal structures with long c-axes. While MAX-phase synthesis at 800 °C is significantly lower than contemporary bulk sintering processes, a reduction of the substrate temperature towards 300 °C in the present thin-film deposition experiments resulted in stacking sequence variations and the intergrowth of (Ti,Al)C. © 2006 Elsevier B.V. All rights reserved.
44.	Zhang, Xiaofu, et al. (författare) Suppression of the transition to superconductivity in crystal/glass high-entropy alloy nanocomposites 2022 Ingår i: Communications Physics. - : NATURE PORTFOLIO. - 2399-3650. ; 5:1 Tidskriftsartikel (refereegranskat)abstract High entropy alloys are multielement materials exhibiting enhanced properties compared to their binary or ternary equivalents. Here, the authors investigate the influence of microstructure and elemental distribution on the transport and superconducting properties of (TaNb)(1-x)(ZrHfTi)(x) thin films. Superconducting high entropy alloys (HEAs) may combine extraordinary mechanical properties with robust superconductivity. They are suitable model systems for the investigation of the interplay of disorder and superconductivity. Here, we report on the superconductivity in (TaNb)(1-x)(ZrHfTi)(x) thin films. Beyond the near-equimolar region, the films comprise hundreds-of-nanometer-sized crystalline grains and show robust bulk superconductivity. However, the superconducting transitions in these nanocomposites are dramatically suppressed in the near-equimolar configurations, i.e., 0.45 < x < 0.64, where elemental distributions are equivalently homogeneous. Crystal/glass high entropy alloy nanocomposite phase separation was observed for the films in the near-equimolar region, which yields a broadened two-step normal to superconducting transition. Furthermore, the diamagnetic shielding in these films is only observed far below the onset temperature of superconductivity. As these unusual superconducting transitions are observed only in the samples with the high mixing entropy, this compositional range influences the collective electronic properties in these materials.
45.	Zhou, Jie, et al. (författare) Two-Dimensional Hydroxyl-Functionalized and Carbon-Deficient Scandium Carbide, ScCxOH, a Direct Band Gap Semiconductor 2019 Ingår i: ACS Nano. - : AMER CHEMICAL SOC. - 1936-0851 .- 1936-086X. ; 13:2, s. 1195-1203 Tidskriftsartikel (refereegranskat)abstract Two-dimensional (2D) materials have attracted intense attention in nanoscience and nanotechnology due to their outstanding properties. Among these materials, the emerging family of 2D transition metal carbides, carbonitrides, and nitrides (referred to as MXenes) stands out because of the vast available chemical space for tuning materials chemistry and surface termination, offering opportunities for property tailoring. Specifically, semiconducting properties are needed to enable utilization in optoelectronics, but direct band gaps are experimentally challenging to achieve in these 2D carbides. Here, we demonstrate the fabrication of 2D hydroxyl-functionalized and carbon-deficient scandium carbide, namely, ScCxOH, by selective etching of a layered parent ScAI(3)C(3) compound. The 2D configuration is determined as a direct band gap semiconductor, with an experimentally measured band gap approximated at 2.5 eV. Furthermore, this ScCxOH-based device exhibits excellent photoresponse in the ultraviolet-visible light region (responsivity of 0.125 A/W at 360 nm/10 V, and quantum efficiency of 43%). Thus, this 2D ScCxOH direct band gap semiconductor may find applications in visible light detectors, photocatalytic chemistry, and optoelectronic devices.
46.	Zhu, Yongbin, et al. (författare) Enhanced Thermoelectric Properties of Mg2Sn-Mg3Sb2 Nanocomposites by Tailoring Matrix/Inclusion Interface toward Energy Harvesting Applications 2023 Ingår i: ACS Applied Nano Materials. - : AMER CHEMICAL SOC. - 2574-0970. ; 6:7, s. 6133-6140 Tidskriftsartikel (refereegranskat)abstract Nanocomposites have been long exploited for achieving balanced material properties. Here, we synthesized nominal (Mg2Sn0.85Sb0.15)1-x-(Mg3Sb2)x (x = 0-0.15) nano-composites, achieving a significant reduction of the lattice thermal conductivity of Mg2Sn0.85Sb0.15 from 2.03 Wm-1K-1 to 1.38 Wm-1K-1 due to phonon scattering by VMg point defects, Mg3Sb2 nanoparticles, and heterogeneous interfaces. Hence, a significantly enhanced thermoelectric figure of merit, ZT, is achieved. At 773 K, the sample of x = 0.075 reaches a ZT of 1.4, corresponding to a 14% enhancement compared to the Mg2Sn0.85Sb0.15 (x = 0) sample. The strategy of introducing heterogeneous structures has important implications for reducing thermal conductivity for other solid-solution thermoelectric systems.
47.	Abramian, David, 1992-, et al. (författare) Anatomically Informed Bayesian Spatial Priors for FMRI Analysis 2020 Ingår i: ISBI 2020. - : IEEE. - 9781538693308 Konferensbidrag (refereegranskat)abstract Existing Bayesian spatial priors for functional magnetic resonance imaging (fMRI) data correspond to stationary isotropic smoothing filters that may oversmooth at anatomical boundaries. We propose two anatomically informed Bayesian spatial models for fMRI data with local smoothing in each voxel based on a tensor field estimated from a T1-weighted anatomical image. We show that our anatomically informed Bayesian spatial models results in posterior probability maps that follow the anatomical structure.
48.	Ahl, Amanda, et al. (författare) Balancing formal and informal success factors perceived by supply chain stakeholders : A study of woody biomass energy systems in Japan 2018 Ingår i: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 175, s. 50-59 Tidskriftsartikel (refereegranskat)abstract Small-scale woody biomass energy systems have an inherent ability to aid in emissions reduction while stimulating local economies and, as collective energy systems, are strongly connected to supply chain design based on local conditions and stakeholder integration. Despite an abundance of forest area alongside the promotion of biomass in energy policies, however, woody biomass utilization still remains low in Japan. The woody biomass supply chain, considered as a socio-technical system, involves a complex, cross-sectoral stakeholder network in which inter-organizational dynamics necessitates well-organized management based on an understanding of formal factors such as technology, as well as informal factors such as social relations and culture. In this paper, success factor perceptions from across the woody biomass supply chain are investigated based on semi-structured interviews with four stakeholders in the Kyushu region of Japan. Identified success factors here are: 1) respect of values & traditions, 2) transportation infrastructure, 3) business model integration, 4) relationship & trust, 5) local vitalization and 6) biomass quality control. A convergence as well as divergence of perceptions are observed, involving both formal and informal dimensions. Aiming to balance perceptions and to enable long-term success of woody biomass in Japan, a series of policy implications are drawn, including cross-ministerial integration, knowledge building on wood logistics, forest certification, local coordinators, biomass quality control standards and a feed-in-tariff for heat. This paper suggests a new arena of policy-making based on the importance of considering both informal and formal dimensions in energy policy.
49.	Akselsson, Roland, et al. (författare) Multidisciplinary Research on Integration of Human Factors and Production Concepts such as TQM - A Participatory Discussion Session 1999 Ingår i: Proceedings of the Conference on TQM and Human Factors. - 9172195207 ; 2, s. 439-448 Konferensbidrag (refereegranskat)abstract A discussion session where the conference participants are invited to participate is planned. One topic for the session is to discuss experiences of multidisciplinary research on integration of human factors and different production concepts applied in change processes within Swedish companies. An important question that the discussion will focus on is: How to get high quality in multidisciplinary research? Another topic is to discuss how people from different disciplines in the companies interact with each other and with the researchers. Researchers from the centre Change@Work at Lund University in Sweden will present some of their experiences from several years of multidisciplinary research in companies. As a background the research questions within Change@Work are presented below. Discussions during the workshop will be performed according to methods used by the researchers in their research in the companies. All discussion will be documented and later sent to all workshop participants.
50.	Alami, Jones, et al. (författare) High-power impulse magnetron sputtering of Ti-Si-C thin films from a Ti3SiC2 compound target 2006 Ingår i: Thin Solid Films. - : Institutionen för fysik, kemi och biologi. - 0040-6090 .- 1879-2731. ; 515:4, s. 1731-1736 Tidskriftsartikel (refereegranskat)abstract We have deposited Ti-Si-C thin films using high-power impulse magnetron sputtering (HIPIMS) from a Ti3SiC2 compound target. The as-deposited films were composite materials with TiC as the main crystalline constituent. X-ray diffraction and photoelectron spectroscopy indicated that they also contained amorphous SiC, and for films deposited on inclined substrates, crystalline Ti5Si3Cx. The film morphology was dense and flat, while films deposited with dc magnetron sputtering under comparable conditions were rough and porous. Due to the high degree of ionization of the sputtered species obtained in HIPIMS, it is possible to control the film composition, in particular the C content, by tuning the substrate inclination angle, the Ar process pressure, and the bias voltage.

Skapa referenser, mejla, bekava och länka

Länka till träfflistan

Träfflista för sökning "WFRF:(Eklund Per) "

Avgränsa träffmängd

År