TY - JOUR
T1 - Inherent instability by antibonding coupling in AgSbTe2
AU - Shinya, Hikari
AU - Masago, Akira
AU - Fukushima, Tetsuya
AU - Katayama-Yoshida, Hiroshi
N1 - Funding Information:
This work was partly supported by the Advanced Low Carbon Technology Research and Development Program (ALCA), "High-efficiency Energy Conversion by Spinodal Nano-decomposition", of Japan Science and Technology Agency (JST), and by Japan Society for the Promotion of Science (JSPS) Grants-in-Aid for Scientific Research (KAKENHI) Grant Number A242260090. This work was partly supported by JSPS Core-to-Core Program (A) Advanced Research Networks ("Computational Nano-materials Design on Green Energy"). T.F. thanks the supports from "Professional development Consortium for Computational Materials Scientists (PCoMS)". The crystal structure and maximally localized Wannier functions in this paper are plotted by using the software VESTA.
Publisher Copyright:
© 2016 The Japan Society of Applied Physics.
PY - 2016/4
Y1 - 2016/4
N2 - In the present paper, an inherent instability in the ternary chalcogenide compound AgSbTe2 is described from the electronic structure viewpoint. Our calculations, which are based on the cluster expansion method, suggest nine stable crystal structures involving the most stable structure with Fd3m symmetry. The effective pair interactions calculated by the generalized perturbation method point out that the stability of these structures originates from the number of linear arrangements of the Ag-Te-Sb atomic bonds. Moreover, it is found that AgSbTe2 has a special electronic structure, where the dominant components of the top of the valence band are the Te-5p antibonding states. Such an antibonding contribution leads to an inherent instability, such that the system spontaneously forms various mutation phases caused by charge-compensated defect complexes. We propose that these mutation phases play an important role in the thermal conductivity and thermoelectric efficiency in AgSbTe2.
AB - In the present paper, an inherent instability in the ternary chalcogenide compound AgSbTe2 is described from the electronic structure viewpoint. Our calculations, which are based on the cluster expansion method, suggest nine stable crystal structures involving the most stable structure with Fd3m symmetry. The effective pair interactions calculated by the generalized perturbation method point out that the stability of these structures originates from the number of linear arrangements of the Ag-Te-Sb atomic bonds. Moreover, it is found that AgSbTe2 has a special electronic structure, where the dominant components of the top of the valence band are the Te-5p antibonding states. Such an antibonding contribution leads to an inherent instability, such that the system spontaneously forms various mutation phases caused by charge-compensated defect complexes. We propose that these mutation phases play an important role in the thermal conductivity and thermoelectric efficiency in AgSbTe2.
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U2 - 10.7567/JJAP.55.041801
DO - 10.7567/JJAP.55.041801
M3 - Article
AN - SCOPUS:84963507356
VL - 55
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 4
M1 - 041801
ER -