Ab initio electronic structure calculations based on density functional theory and tight-binding methods for the thermoelectric properties of p-type Sb2Te3 films are presented. The thickness-dependent electrical conductivity and the thermopower are computed in the diffusive limit of transport based on the Boltzmann equation. Contributions of the bulk and the surface to the transport coefficients are separated, which enables to identify a clear impact of the topological surface state on the thermoelectric properties. When the charge carrier concentration is tuned, a crossover between a surface-state-dominant and a Fuchs-Sondheimer transport regime is achieved. The calculations are corroborated by thermoelectric transport measurements on Sb2Te3 films grown by atomic layer deposition.
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http://dx.doi.org/10.1021/acsnano.5b00896 | DOI Listing |
Heliyon
January 2025
Department of Mathematics, Faculty of Sciences, Ghazi University, Dera Ghazi Khan, 32200, Pakistan.
Chemical structures may be defined based on their topology, which allows for the organization of molecules and the representation of new structures with specific properties. We use topological indices, which are precise numerical measurements independent of structure, to measure the bonding arrangement of a chemical network. An essential objective of studying topological indices is to collect and alter chemical structure data to develop a mathematical relationship between structures and physico-chemical properties, bio-activities, and associated experimental factors.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
College of Environment, Zhejiang University of Technology, Hangzhou 310032, P. R. of China.
Soil microbiota plays crucial roles in maintaining the health, productivity, and nutrient cycling of terrestrial ecosystems. The persistence and prevalence of heterocyclic compounds in soil pose significant risks to soil health. However, understanding the links between heterocyclic compounds and microbial responses remains challenging due to the complexity of microbial communities and their various chemical structures.
View Article and Find Full Text PDFNat Commun
January 2025
School of Materials Science and Engineering, Peking University, Beijing, P.R. China.
Designing catalysts with well-defined, identical sites that achieve site-specific selectivity, and activity remains a significant challenge. In this work, we introduce a design principle of topological-single-atom catalysts (T-SACs) guided by density functional theory (DFT) and Ab initio molecular dynamics (AIMD) calculations, where metal single atoms are arranged in asymmetric configurations that electronic shield topologically misorients d orbitals, minimizing unwanted interactions between reactants and the support surface. Mn/CeO catalysts, synthesized via a charge-transfer-driven approach, demonstrate superior catalytic activity and selectivity for NO removal.
View Article and Find Full Text PDFACS Nano
January 2025
School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni 752050, India.
Topological magnetic skyrmions with helicity state degrees of freedom in centrosymmetric magnets possess great potential for advanced spintronics applications and quantum computing. Till date, the skyrmion study in this class of materials mostly remains focused to collinear ferromagnets with uniaxial magnetic anisotropy. Here, we present a combined theoretical and experimental study on the competing magnetic exchange-induced evolution of noncollinear magnetic ground states and its impact on the skyrmion formation in a series of centrosymmetric hexagonal noncollinear magnets, MnFeCoGe.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305.
A central paradigm of nonequilibrium physics concerns the dynamics of heterogeneity and disorder, impacting processes ranging from the behavior of glasses to the emergent functionality of active matter. Understanding these complex mesoscopic systems requires probing the microscopic trajectories associated with irreversible processes, the role of fluctuations and entropy growth, and the timescales on which nonequilibrium responses are ultimately maintained. Approaches that illuminate these processes in model systems may enable a more general understanding of other heterogeneous nonequilibrium phenomena, and potentially define ultimate speed and energy cost limits for information processing technologies.
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