Title: Temperature dependence of structural, dynamical, and electronic properties of amorphous Bi ₂Te ₃: an ab initio study

Abstract

Bismuth telluride (Bi ₂Te ₃) has garnered significant interest in thermoelectric applications and three-dimensional topological insulators due to its unique electronic, transport, and thermal properties. Bi ₂Te ₃ and Sb ₂Te ₃ chalcogenide compounds have the same crystal structure. While Sb ₂Te ₃ has been shown to be a prototypical phase change memory (PCM) compound along the pseudobinary tie-line of Ge-Sb-Te alloys, whether Bi ₂Te ₃ can also exhibit PCM functionality is still not well established. In this work, a systematic study on the structural, dynamical, and electronic properties of amorphous Bi ₂Te ₃ during the quenching process has been performed by using ab initio molecular dynamics simulations. Pair correlation function, coordination number, bond-angle distribution functions, and a novel atomistic cluster alignment method are used to explore the structural characteristics of Bi ₂Te ₃ as a function of temperature. Our study shows that there are many distorted octahedral clusters in amorphous Bi ₂Te ₃. In comparison with the local structures in Sb ₂Te ₃, we found that the degree of distortion of the octahedrons in the Bi ₂Te ₃ system is smaller than that in Sb ₂Te ₃ system. Moreover, the changes in the dynamical properties of Bi ₂Te ₃more » from liquid to glassy state are also explored. The approximate range of liquid-to-glass transition temperature is determined to be between 673 and 723 K. The electronic properties of Bi2Te ₃ and Sb ₂Te ₃ are also analysed by density-of-states and Bader charge calculations, both of them in glass state are semiconductors. Our studies provide useful insights into the local structure and dynamical properties of Bi ₂Te ₃ at the atomistic level during the fast cooling process, and suggest that the compound can be a candidate for PCM materials.« less

Authors:

Guo, Y. R.  ^[1];

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Qiao, Chong ^[1]; Wang, J. J. ^[1]; Shen, H. ^[1]; Wang, S. Y. ^[2]; Zheng, Y. X. ^[1]; Zhang, R. J. ^[1]; Chen, L. Y. ^[1]; Su, Wan-Sheng  ^[3];

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• Search DOE PAGES for ORCID "0000-0002-9359-8966"
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Wang, C. Z.  ^[4];

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Ho, K. M. ^[4]

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+ Show Author Affiliations

1. Fudan Univ., Shanghai (China)
2. Fudan Univ., Shanghai (China); Key Lab. for Information Science of Electromagnetic Waves (MoE), Shanghai (China)
3. National Taiwan Univ., Taipei (Taiwan); Taiwan Semiconductor Research Inst., Hsinchu (Taiwan)
4. Ames Lab., and Iowa State Univ., Ames, IA (United States)

Publication Date:

2019-09-30

Research Org.:

Ames Laboratory (AMES), Ames, IA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; NSF of China

OSTI Identifier:

1580525

Report Number(s):

IS-J-10,115
Journal ID: ISSN 1367-2630

Grant/Contract Number:  

AC02-07CH11358

Resource Type:

Accepted Manuscript

Journal Name:

New Journal of Physics

Additional Journal Information:

Journal Volume: 21; Journal Issue: 9; Journal ID: ISSN 1367-2630

Publisher:

IOP Publishing

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; ab initio molecular dynamics; liquid materials; local structure; dynamical properties