| 1. |
- Fallqvist, Mikael, et al.
(författare)
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Nucleation And Growth Of Cvd α-Al2O3 On TiXOY Template
- 2012
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Ingår i: Surface & Coatings Technology. - : Elsevier. - 0257-8972 .- 1879-3347. ; 207, s. 254-261
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Tidskriftsartikel (refereegranskat)abstract
- The microstructure, phase and chemical composition of TixOy templates used to nucleate α-Al2O3 on Ti(C,N) coated cemented carbide have been elucidated using scanning electron microscopy, X-ray diffraction, Auger electron spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry. Further, the adhesive strength of the α-Al2O3–TixOy–Ti(C,N) interfaces was investigated using scratch adhesion testing.The present study confirmed that the as-deposited template consisted of a Ti4O7 phase which during subsequent deposition of the Al2O3 layer transformed to a Ti3O5 phase and that the grown Al2O3 layer consisted of 100% α-Al2O3. Furthermore, the results showed that the lowest interfacial strength within the multilayer structure was exhibited by the Ti(C,N)–TixOy interface and that the transformation of Ti4O7 to Ti3O5 in the template resulted in formation of pores in the Ti(C,N)-template interface lowering the interfacial strength even more. The use of surface analysis techniques such as Auger electron spectroscopy and especially Time-of-Flight Secondary Ion Mass Spectrometry enabled trace element analyses using depth profiling to characterise the thin interfacial layers in detail.
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| 2. |
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| 3. |
- Chulapakorn, Thawatchart, 1988-, et al.
(författare)
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Luminescence of silicon nanoparticles from oxygen implanted silicon
- 2018
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Ingår i: Materials Science in Semiconductor Processing. - : Elsevier. - 1369-8001 .- 1873-4081. ; 86, s. 18-22
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Tidskriftsartikel (refereegranskat)abstract
- Oxygen with a kinetic energy of 20 keV is implanted in a silicon wafer (100) at different fluences, followed by post-implantation thermal annealing (PIA) performed at temperatures ranging from 1000 to 1200 degrees C, in order to form luminescent silicon nanoparticles (SiNPs) and also to reduce the damage induced by the implantation. As a result of this procedure, a surface SiOx layer (with 0 < x < 2) with embedded crystalline Si nanoparticles has been created. The samples yield similar luminescence in terms of peak wavelength, lifetime, and absorption as recorded from SiNPs obtained by the more conventional method of implanting silicon into silicon dioxide. The oxygen implantation profile is characterized by elastic recoil detection (ERD) technique to obtain the excess concentration of Si in a presumed SiO2 environment. The physical structure of the implanted Si wafer is examined by grazing incidence X-ray diffraction (GIXRD). Photoluminescence (PL) techniques, including PL spectroscopy, time-resolved PL (TRPL), and photoluminescence excitation (PLE) spectroscopy are carried out in order to identify the PL origin. The results show that luminescent SiNPs are formed in a Si sample implanted by oxygen with a fluence of 2 x 10(17) atoms cm(-2) and PIA at 1000 degrees C. These SiNPs have a broad size range of 6-24 nm, as evaluated from the GIXRD result. Samples implanted at a lower fluence and/or annealed at higher temperature show only weak defect-related PL. With further optimization of the SiNP luminescence, the method may offer a simple route for integration of luminescent Si in mainstream semiconductor fabrication.
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| 4. |
- Farkas, B., et al.
(författare)
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Optical, compositional and structural properties of pulsed laser deposited nitrogen-doped Titanium-dioxide
- 2018
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Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 433, s. 149-154
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Tidskriftsartikel (refereegranskat)abstract
- N-doped TiO2 thin films were prepared using pulsed laser deposition by ablating metallic Ti target with pulses of 248 nm wavelength, at 330 °C substrate temperature in reactive atmospheres of N2/O2 gas mixtures. These films were characterized by spectroscopic ellipsometry, X-ray photoelectron spectroscopy and X-ray diffraction. Optical properties are presented as a function of the N2 content in the processing gas mixture and correlated to nitrogen incorporation into the deposited layers. The optical band gap values decreased with increasing N concentration in the films, while a monotonically increasing tendency and a maximum can be observed in case of extinction coefficient and refractive index, respectively. It is also shown that the amount of substitutional N can be increased up to 7.7 at.%, but the higher dopant concentration inhibits the crystallization of the samples.
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| 5. |
- Hedin, Allan, et al.
(författare)
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Corrosion of copper in pure O2-free water?
- 2018
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Ingår i: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 137, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- Copper exposed to pure, O-2-free water for several months in glass- and metal-contained, well-controlled systems shows no evidence of corrosion, either through hydrogen evolution or through the occurrence of oxidized copper. The results contradict the interpretation of recent experiments where it has been claimed that copper corrodes in pure, O-2-free water far above the very limited extent predicted by established thermodynamic data. Reasons for the different experimental outcomes are discussed. Experimental and theoretical efforts to identify hitherto unknown, potentially corrosion driving species of the Cu-O-H system and studies of copper/water surface reactions are reviewed as background for the present study.
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| 6. |
- Lindahl, Erik, 1979-, et al.
(författare)
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Doping of metastable Cu3N at different Ni concentrations : Growth, crystallographic sites and resistivity
- 2018
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Ingår i: Thin Solid Films. - : ELSEVIER SCIENCE SA. - 0040-6090 .- 1879-2731. ; 647, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Copper nitride, Cu3N, is a metastable material whose properties can be changed considerably by doping with metals which opens for a variety of applications in several areas (sensors, electrical connects, batteries, memories, etc.). The present work is a systematic study in the system Cu-Ni-N of preferences regarding occupation of interstitial and substitutional crystallographic sites in the Cu3N structure as the metal dopant level increases and how the occupation influences growth behavior, texture, microstructure and resistivity. Ni doped Cu3N films of different chemical composition were grown by a gas-pulsed Chemical Vapor Deposition technique. The occupation of the different crystallographic sites of the Cu3N by the Ni atoms was obtained from analysis of X-ray diffraction data. At low Ni content, less than about 21% in metal content, Ni replaced the Cu atoms in the structure. In the intermediate Ni metal content range from about 21 to 40% the vacant centre position became available. After filling the centre position, substitution of Cu for Ni occurred up to a Ni content of about 80% (Cu0.8Ni3.2N) which is the solid solubility limit of Ni in Cu3N. The film resistivity decreased rapidly by adding nickel to the Cu3N structure from about 10(9)mu Omega.cm without any Ni doping to about 100 mu Omega.cm with 80% Ni in the metal content. After filling the centre position the change in resistivity when Cu atoms were substituted for Ni was very small. Finally, the growth mechanism, texture and microstructure changed significantly with the uptake of Ni atoms in the structure.
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| 7. |
- Lindahl, Erik, et al.
(författare)
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Gas-Pulsed CVD for Film Growth in the Cu-Ni-N System
- 2012
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Ingår i: Chemical Vapor Deposition. - : Wiley. - 0948-1907 .- 1521-3862. ; 18:1-3, s. 10-16
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Tidskriftsartikel (refereegranskat)abstract
- A new ternary solid solution, Cu3-xNix+yN, is prepared by gas-pulsed CVD at 260 degrees C. Gas pulses of the precursor mixtures Cu(hfac)2+NH3 and Ni(thd)2+NH3, separated by intermittent ammonia pulses, are employed for the deposition of Cu3N and Ni3N, respectively. A few monolayers of the nitrides are grown in each CVD pulse and then mixed by diffusion to produce the solid solution. The metal content of the solid solution can be varied continuously from 100% to about 20% Cu, which means that the electrical properties can be varied from 1.6eV (band gap of Cu3N) to metallic (Ni3N). This is of interest for various applications, e.g., solar energy, catalysis, and microelectronics.
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| 8. |
- Magnusson, Thomas, 1970-, et al.
(författare)
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Ensuring protection and competitiveness : Characteristics of market formation for biogas
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Background and research questionPresenting possible solutions to environmental problems such as air quality, greenhouse gases, nutrient recirculation, organic waste and wastewater management, biogas is highly relevant for sustainability transitions. Besides biogas producers, the production and use of biogas engages actors from several sectors, including energy and gas distribution, waste management and wastewater treatment, agriculture, vehicles and transport.The formation of markets for biogas depends on policy interventions at different levels, from the local municipality via the national government to the EU commission. By contrast to other European countries, which tend to subsidize biogas production, the Swedish government has the intention to stimulate demand and to favor the use of purified biogas (biomethane) as a vehicle fuel. While biomethane currently has a strong position as an alternative to fossil fuels in certain niches (notably public transport buses), the Swedish biogas sector faces challenges to reach beyond these narrow market segments.Adopting a market constructivist perspective, this paper will analyze the formation of markets for biogas in Sweden. The following research question will guide the analysis: What characterizes market formation in this case and based on that, what is possible to learn about market formation in relation to sustainability transitions? TheoryMarketing scholars increasingly consider market formation as on-going processes, which a multitude of actors influence through their strategies, activities and capabilities. To understand market formation it is therefore necessary to analyze activities among a wider array of actors than merely producers and their (potential) customers.Following a constructivist perspective, the offer is a core element in market formation. The offer describes the meanings and qualifications that actors impose on the object that is for sale. These meanings and qualifications constitute boundaries between actors and goods. Different actors engage to define the object, as well as its meanings, qualifications and potential value. Without a clear view of what is being exchanged, market formation will be difficult. Market formation also includes institutions that set boundaries and rules for the market. These are neither static, nor pre-conceived; instead, they are shaped and acted upon. Actors influence institutions through dynamic and interactive processes. MethodThe paper combines quantitative and qualitative sources of data to study the Swedish biogas sector. The paper presents detailed data on production and use of biogas in Sweden 2010-2017. This quantitative data is complemented by qualitative data from interviews with representatives from key actors as well as secondary data from industry reports and other written sources. FindingsThe multitude of actors involved complicates market formation for biogas. Different meanings and qualifications are attributed to the offer. Whereas it is possible to perceive biogas as a relatively simple product – a fuel – it is also possible to perceive it as a complex system that may help solving various societal and environmental problems. Different perceptions of the offer have different implications for market formation. Depicting biogas as a complex system implies that the offer will comprise a number of different qualifications. The realization of such a complex system depends on the bonding of various actors. Once established, the bonds will protect biogas from competition. By contrast, depicting biogas as a fuel means that the value of biogas will be assessed in relation to fuel prices. Qualification will thus depend on cost competitiveness vis-a-vis other fuels.Our analysis suggests that although the contrasting perceptions of biogas cause tensions between the actors involved, the different qualifications complement each other in the market formation process. Various environmental and societal benefits makes it possible for actors argue for institutional reforms to help biogas become cost competitive, and increased competitiveness makes it attractive to establish new biogas systems.
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| 9. |
- Magnusson, Thomas, 1970-, et al.
(författare)
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Industrial ecology and the boundaries of the manufacturing firm
- 2019
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Ingår i: Journal of Industrial Ecology. - : Wiley-Blackwell Publishing Inc.. - 1088-1980 .- 1530-9290. ; 23:5, s. 1211-1225
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Tidskriftsartikel (refereegranskat)abstract
- Decisions on organizational boundaries are critical aspects of manufacturing firms’ business strategies. This article brings together concepts and findings from industrial ecology and business strategy in order to understand how manufacturing firms engage in initiatives to facilitate recycling of process wastes. Based on a distinction between waste recovery and use of the recovered resources, the article introduces a typology of four different strategies: Closed, Outsourcing, Diversification, and Open. Each strategy has a unique set of organizational boundaries and is associated with different motives and benefits for the manufacturing firm. The typology of strategies provides a conceptual contribution to assist industrial managers in strategic decision-making, and to support further studies on organizational boundaries in industrial ecology research.
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| 10. |
- Mukhamedov, Boburjon, et al.
(författare)
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Tetragonal distortion in magnetron sputtered bcc-W films with supersaturated carbon
- 2022
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Ingår i: Materials & design. - : Elsevier Science Ltd. - 0264-1275 .- 1873-4197. ; 214
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Tidskriftsartikel (refereegranskat)abstract
- Carbon has a low solid solubility in bcc tungsten at equilibrium. However, metastable supersaturated solid solutions can be synthesized with magnetron sputtering. Here, we present a systematic study on the phase stability and mechanical properties of such supersaturated W-C solid solutions. H-2h scans show a split of the 200/020 and the 002 peaks for supersaturated films which is explained by a tetragonal distortion of the bcc structure. This split increases with increasing C content and is maximized at 4 at.% C, where we observe an a/b axis of 3.15-3.16 A and a c-axis of 3.21-3.22 A. We performed first-principles calculations of lattice parameters, mixing enthalpies, elastic constants and polycrystalline elastic moduli for cubic and tetragonal W-C solid solutions. Calculations show that tetragonal structure is more stable than the bcc supersaturated solid solution and the calculated lattice parameters and Youngs moduli follow the same trends as the experimental ones as a function of C concentration. The results suggest that supersaturated films with lattice distortion can be used as a design approach to improve the properties of transition metal films with a bcc structure. (c) 2022 The Authors. Published by Elsevier Ltd.
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