TY - JOUR
T1 - First-principles study of electronic transport and structural properties of Cu12Sb4 S13 in its high-temperature phase
AU - Di Paola, Cono
AU - MacHeda, Francesco
AU - Laricchia, Savio
AU - Weber, Cedric
AU - Bonini, Nicola
N1 - Publisher Copyright:
© 2020 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2020/7
Y1 - 2020/7
N2 - We present an ab initio study of the structural and electronic transport properties of tetrahedrite, Cu12Sb4S13, in its high-temperature phase. We show how this complex compound can be seen as the outcome of an ordered arrangement of S-vacancies in a semiconducting fematinite-like structure (Cu3SbS4). Our calculations confirm that the S-vacancies are the natural doping mechanism in this thermoelectric compound and reveal a similar local chemical environment around crystallographically inequivalent Cu atoms, shedding light on the debate on X-ray photoelectron spectroscopy measurements in this compound. To access the electrical transport properties as a function of temperature we use the Kubo-Greenwood formula applied to snapshots of first-principles molecular dynamics simulations. This approach is essential to effectively account for the interaction between electrons and lattice vibrations in such a complex crystal structure where a strong anharmonicity plays a key role in stabilizing the high-temperature phase. Our results show that the Seebeck coefficient is in good agreement with experiments and the phonon-limited electrical resistivity displays a temperature trend that compares well with a wide range of experimental data. The predicted lower bound for the resistivity turns out to be remarkably low for a pristine mineral in the Cu-Sb-S system but not too far from the lowest experimental data reported in literature. The Lorenz number turns out to be substantially lower than what is expected from the free-electron value in the Wiedemann-Franz law, thus providing an accurate way to estimate the electronic and lattice contributions to the thermal conductivity in experiments, of great significance in this very low thermal conductivity crystalline material.
AB - We present an ab initio study of the structural and electronic transport properties of tetrahedrite, Cu12Sb4S13, in its high-temperature phase. We show how this complex compound can be seen as the outcome of an ordered arrangement of S-vacancies in a semiconducting fematinite-like structure (Cu3SbS4). Our calculations confirm that the S-vacancies are the natural doping mechanism in this thermoelectric compound and reveal a similar local chemical environment around crystallographically inequivalent Cu atoms, shedding light on the debate on X-ray photoelectron spectroscopy measurements in this compound. To access the electrical transport properties as a function of temperature we use the Kubo-Greenwood formula applied to snapshots of first-principles molecular dynamics simulations. This approach is essential to effectively account for the interaction between electrons and lattice vibrations in such a complex crystal structure where a strong anharmonicity plays a key role in stabilizing the high-temperature phase. Our results show that the Seebeck coefficient is in good agreement with experiments and the phonon-limited electrical resistivity displays a temperature trend that compares well with a wide range of experimental data. The predicted lower bound for the resistivity turns out to be remarkably low for a pristine mineral in the Cu-Sb-S system but not too far from the lowest experimental data reported in literature. The Lorenz number turns out to be substantially lower than what is expected from the free-electron value in the Wiedemann-Franz law, thus providing an accurate way to estimate the electronic and lattice contributions to the thermal conductivity in experiments, of great significance in this very low thermal conductivity crystalline material.
UR - http://www.scopus.com/inward/record.url?scp=85101363398&partnerID=8YFLogxK
U2 - 10.1103/PhysRevResearch.2.033055
DO - 10.1103/PhysRevResearch.2.033055
M3 - Article
AN - SCOPUS:85101363398
SN - 2643-1564
VL - 2
JO - Physical Review Research
JF - Physical Review Research
IS - 3
M1 - 033055
ER -