| 1. |
- Coll, M., et al.
(författare)
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Towards Oxide Electronics: a Roadmap
- 2019
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Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 482, s. 1-93
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Tidskriftsartikel (refereegranskat)abstract
- At the end of a rush lasting over half a century, in which CMOS technology has been experiencing a constant and breathtaking increase of device speed and density, Moore’s law is approaching the insurmountable barrier given by the ultimate atomic nature of matter. A major challenge for 21st century scientists is finding novel strategies, concepts and materials for replacing silicon-based CMOS semiconductor technologies and guaranteeing a continued and steady technological progress in next decades. Among the materials classes candidate to contribute to this momentous challenge, oxide films and heterostructures are a particularly appealing hunting ground. The vastity, intended in pure chemical terms, of this class of compounds, the complexity of their correlated behaviour, and the wealth of functional properties they display, has already made these systems the subject of choice, worldwide, of a strongly networked, dynamic and interdisciplinary research community. Oxide science and technology has been the target of a wide four-year project, named Towards Oxide-Based Electronics (TO-BE), that has been recently running in Europe and has involved as participants several hundred scientists from 29 EU countries. In this review and perspective paper, published as a final deliverable of the TO-BE Action, the opportunities of oxides as future electronic materials for Information and Communication Technologies ICT and Energy are discussed. The paper is organized as a set of contributions, all selected and ordered as individual building blocks of a wider general scheme. After a brief preface by the editors and an introductory contribution, two sections follow. The first is mainly devoted to providing a perspective on the latest theoretical and experimental methods that are employed to investigate oxides and to produce oxide-based films, heterostructures and devices. In the second, all contributions are dedicated to different specific fields of applications of oxide thin films and heterostructures, in sectors as data storage and computing, optics and plasmonics, magnonics, energy conversion and harvesting, and power electronics.
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| 2. |
- Halder, S., et al.
(författare)
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Control of Dy 164 Bose-Einstein condensate phases and dynamics with dipolar anisotropy
- 2022
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Ingår i: Physical Review Research. - 2643-1564. ; 4:4
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the quench dynamics of quasi-one- and two-dimensional dipolar Bose-Einstein condensates of Dy164 atoms under the influence of a fast rotating magnetic field. The magnetic field thus controls both the magnitude and sign of the dipolar potential. We account for quantum fluctuations, critical to formation of exotic quantum droplet and supersolid phases in the extended Gross-Pitaevskii formalism, which includes the so-called Lee-Huang-Yang correction. An analytical variational ansatz allows us to obtain the phase diagrams of the superfluid and droplet phases. The crossover from the superfluid to the supersolid phase and to single and droplet arrays is probed with particle number and dipolar interaction. The dipolar strength is tuned by rotating the magnetic field with subsequent effects on phase boundaries. Following interaction quenches across the aforementioned phases, we monitor the dynamical formation of supersolid clusters or droplet lattices. We include losses due to three-body recombination over the crossover regime, where the three-body recombination rate coefficient scales with the fourth power of the scattering length (as) or the dipole length (add). For fixed values of the dimensionless parameter, ϵdd=add/as, tuning the dipolar anisotropy leads to an enhancement of the droplet lifetimes.
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| 3. |
- Islam, M. S., et al.
(författare)
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Augmenting the sensing aptitude of hydrogenated graphene by crafting with defects and dopants
- 2016
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 228, s. 317-321
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Tidskriftsartikel (refereegranskat)abstract
- Density functional theory (DFT) level calculations were performed to study the interaction of hydrogenated graphene (CH) monolayer towards methane (CH4) gas molecules. The structural, electronic and gas sensing properties of pure, defected and light metal-doped CH monolayer were investigated. For the pristine CH, the estimated binding energy of CH4 fell short of the desired physisorption range and limit its gas sensing application at ambient conditions. However, upon crafting defects on pure CH layer by introducing hydrogen vacancies, a sharp increase in adsorption energies were observed when the CH4 molecules approached the defected sites of CH. Further, the effect of metal doping was studied by uniformly distributing light metal adatoms on CH monolayer which significantly enhanced the CH4 adsorption. To have better accuracy in calculating adsorption energies, we have incorporated van der Waals type corrections to our calculations for these weakly interacting systems.
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| 4. |
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| 5. |
- Panigrahi, P., et al.
(författare)
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Light metal decorated graphdiyne nanosheets for reversible hydrogen storage
- 2018
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Ingår i: Nanotechnology. - : Institute of Physics (IOP). - 0957-4484 .- 1361-6528. ; 29:35
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Tidskriftsartikel (refereegranskat)abstract
- The sensitive nature of molecular hydrogen (H-2) interaction with the surfaces of pristine and functionalized nanostructures, especially two-dimensional materials, has been a subject of debate for a while now. An accurate approximation of the H-2 adsorption mechanism has vital significance for fields such as H2 storage applications. Owing to the importance of this issue, we have performed a comprehensive density functional theory (DFT) study by means of several different approximations to investigate the structural, electronic, charge transfer and energy storage properties of pristine and functionalized graphdiyne (GDY) nanosheets. The dopants considered here include the light metals Li, Na, K, Ca, Sc and Ti, which have a uniform distribution over GDY even at high doping concentration due to their strong binding and charge transfer mechanism. Upon 11% of metal functionalization, GDY changes into a metallic state from being a small band-gap semiconductor. Such situations turn the dopants to a partial positive state, which is favorable for adsorption of H-2 molecules. The adsorption mechanism of H-2 on GDY has been studied and compared by different methods like generalized gradient approximation, van der Waals density functional and DFT-D3 functionals. It has been established that each functionalized system anchors multiple H-2 molecules with adsorption energies that fall into a suitable range regardless of the functional used for approximations. A significantly high H-2 storage capacity would guarantee that light metal-doped GDY nanosheets could serve as efficient and reversible H-2 storage materials.
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| 6. |
- Panigrahi, P., et al.
(författare)
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Tuning the selective sensing properties of transition metal dichalcogenides (MoX2 X= Se, Te) toward sulfurrich gases
- 2022
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Ingår i: Materials Today Chemistry. - : Elsevier. - 2468-5194. ; 26
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Tidskriftsartikel (refereegranskat)abstract
- There is an urgent need for an efficient sensor to mitigate the effects of toxic pollutants possessing severe impacts on humans and the environment. Motivated by this, we investigated the selected transition metal dichalcogenides (MoX2: X = Se, Te) monolayers toward the toxic sulfur-containing gases, such as H2S and SO2. We employed density functional theory simulations in combination with nonequilibrium Green's function formalism to study the optimized geometries, binding strength, electronic structures, charge transfer mechanism, and transport (current-voltage) characteristics of MoX2 with and without H2S and SO2. Weak binding energies (<-0.30 eV) of H2S/SO2 on pristine MoX2 were enhanced by selectively substituting the latter with elements like As, Ge, and Sb at lower doping concentrations of around 2%. We find that the doped MoX2 strongly adsorbs H2S/SO2 yielding significant changes in their electronic properties, which were the fundamentals for the efficient sensing mechanism and were studied through the density of states and work function calculations. For the practical sensing applica-tions, we considered the statistical thermodynamic analysis to investigate the sensing properties of pristine and doped MoX2 monolayers under varied conditions of the temperatures and pressures. We are confident that our findings would pave the way for synthesizing sensitive and selective transition metal dichalcogenides-based nanosensor toward H2S/SO2.
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| 7. |
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| 8. |
- Ragupathi, V., et al.
(författare)
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Enhanced electrochemical performance of LiMnBO3 with conductive glassy phase : a prospective cathode material for lithium-ion battery
- 2017
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Ingår i: Ionics (Kiel). - : Springer. - 0947-7047 .- 1862-0760. ; 23:7, s. 1645-1653
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Tidskriftsartikel (refereegranskat)abstract
- LiMnBO3 has been identified as a promising cathode material for next-generation lithium-ion batteries. In this study, LiMnBO3 along with glassy lithium borate material (LiMnBO3 (II)) is synthesized by sol-gel method. X-ray diffraction (XRD) analysis depicts the existence of LiBO2 glassy phase along with m-LiMnBO3 phase. Transmission electron microscopy (TEM) analysis confirms the presence of LiBO2 glassy phase. An enhanced electrical conductivity of 3.64 x 10(-7) S/cm is observed for LiMnBO3 (II). The LiBO2 glassy phase is found to promote the Li reaction kinetics in LiMnBO3 (II). The synthesized LiMnBO3 (II) delivers a first discharge capacity of 310 mAh g(-1) within a potential window of 1.5-4.5 V at C/10 rate. Further, a discharge capacity of 186 mAh g(-1) at the 27th cycle shows a better cycle performance. The enhanced capacity is due to the presence of LiBO2 glassy phase and more than one Li-ion transfer in the lithium-rich stoichiometry of LiMnBO3 (II). Density functional theory calculation reveals the exact electronic structure of m-LiMnBO3 with a band gap of 3.05 eV. A charge transfer mechanism is predicted for delithiation process of m-LiMnBO3.
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| 9. |
- Heier, C. R., et al.
(författare)
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Multi-Omics Identifies Circulating miRNA and Protein Biomarkers for Facioscapulohumeral Dystrophy
- 2020
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Ingår i: Journal of Personalized Medicine. - : MDPI AG. - 2075-4426. ; 10:4
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Tidskriftsartikel (refereegranskat)abstract
- The development of therapeutics for muscle diseases such as facioscapulohumeral dystrophy (FSHD) is impeded by a lack of objective, minimally invasive biomarkers. Here we identify circulating miRNAs and proteins that are dysregulated in early-onset FSHD patients to develop blood-based molecular biomarkers. Plasma samples from clinically characterized individuals with early-onset FSHD provide a discovery group and are compared to healthy control volunteers. Low-density quantitative polymerase chain reaction (PCR)-based arrays identify 19 candidate miRNAs, while mass spectrometry proteomic analysis identifies 13 candidate proteins. Bioinformatic analysis of chromatin immunoprecipitation (ChIP)-seq data shows that the FSHD-dysregulated DUX4 transcription factor binds to regulatory regions of several candidate miRNAs. This panel of miRNAs also shows ChIP signatures consistent with regulation by additional transcription factors which are up-regulated in FSHD (FOS, EGR1, MYC, and YY1). Validation studies in a separate group of patients with FSHD show consistent up-regulation of miR-100, miR-103, miR-146b, miR-29b, miR-34a, miR-454, miR-505, and miR-576. An increase in the expression of S100A8 protein, an inflammatory regulatory factor and subunit of calprotectin, is validated by Enzyme-Linked Immunosorbent Assay (ELISA). Bioinformatic analyses of proteomics and miRNA data further support a model of calprotectin and toll-like receptor 4 (TLR4) pathway dysregulation in FSHD. Moving forward, this panel of miRNAs, along with S100A8 and calprotectin, merit further investigation as monitoring and pharmacodynamic biomarkers for FSHD.
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| 10. |
- Hussain, Tanveer, et al.
(författare)
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Hydrogen storage properties of light metal adatoms (Li, Na) decorated fluorographene monolayer
- 2015
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 26:27
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Tidskriftsartikel (refereegranskat)abstract
- Owing to its high energy density, the potential of hydrogen (H-2) as an energy carrier has been immense, however its storage remains a big obstacle and calls for an efficient storage medium. By means of density functional theory (DFT) in spin polarized generalized gradient approximation (GGA), we have investigated the structural, electronic and hydrogen storage properties of a light alkali metal (Li, Na) functionalized fluorographene monolayer (FG). Metal adatoms bind to the FG with significantly high binding energy, much higher than their cohesive energies, which helps to achieve a uniform distribution of metal adatoms on the monolayer and consequently ensure reversibility. Due to a difference of electronegativities, each metal adatom transfers a substantial amount of its charge to the FG monolayer and attains a partial positive state, which facilitates the adsorption of multiple H-2 molecules around the adatoms by electrostatic as well as van der Waals interactions. To get a better description of H-2 adsorption energies with metal-doped systems, we have also performed calculations using van der Waals corrections. For both the functionalized systems, the results indicate a reasonably high H-2 storage capacity with H2 adsorption energies falling into the range for the practical applications.
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