skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Pressure induced short-range structural changes in supercooled liquid Ge2Sb2Te5

Abstract

Phase-change material such as Ge2Sb2Te5 is usually utilized to store data due to the pronounced contrast in optical and electrical properties between crystalline and amorphous phases. As the density differs in the two phases, it is necessary to explore the influence of pressure on the structures of Ge2Sb2Te5, especially for the supercooled liquid which is an inevitable state in the formation of the two phases. The short-range structures in supercooled liquid Ge2Sb2Te5 under compression have been investigated by using ab initio molecular dynamics simulation. The supercooled liquid eventually changes to a solid with an increase in pressure. During the process, tetrahedrons decrease slightly, revealing that tetrahedral structures are insensitive to the pressure. Octahedrons increase as the pressure is less than 3.7 GPa and then decrease, suggesting that a moderate pressure can promote the formation of octahedrons. The body-centered-cubic, face-centered-cubic and hexagonal closed-packed structures are observed at 9.9 GPa and then increase gradually. Additionally, it is noticed that Sb- and Te-centered clusters prefer Ge-centered clusters to forming the high-coordinated short-range structures during the compression process. Our research make us aware of the effects of pressure on short-range structures in supercooled liquid, which is of great importance in the application of phase-change materials.

Authors:
; ; ; ; ORCiD logo; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Iowa State Univ., Ames, IA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division
OSTI Identifier:
1543566
DOE Contract Number:  
AC02-07CH11358
Resource Type:
Journal Article
Journal Name:
Journal of Non-Crystalline Solids
Additional Journal Information:
Journal Volume: 503-504; Journal Issue: C; Journal ID: ISSN 0022-3093
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
Materials Science

Citation Formats

Qiao, Chong, Guo, Y. R., Wang, J. J., Shen, H., Wang, S. Y., Zheng, Y. X., Zhang, R. J., Chen, L. Y., Wang, C. Z., and Ho, K. M. Pressure induced short-range structural changes in supercooled liquid Ge2Sb2Te5. United States: N. p., 2019. Web. doi:10.1016/j.jnoncrysol.2018.10.028.
Qiao, Chong, Guo, Y. R., Wang, J. J., Shen, H., Wang, S. Y., Zheng, Y. X., Zhang, R. J., Chen, L. Y., Wang, C. Z., & Ho, K. M. Pressure induced short-range structural changes in supercooled liquid Ge2Sb2Te5. United States. doi:10.1016/j.jnoncrysol.2018.10.028.
Qiao, Chong, Guo, Y. R., Wang, J. J., Shen, H., Wang, S. Y., Zheng, Y. X., Zhang, R. J., Chen, L. Y., Wang, C. Z., and Ho, K. M. Tue . "Pressure induced short-range structural changes in supercooled liquid Ge2Sb2Te5". United States. doi:10.1016/j.jnoncrysol.2018.10.028.
@article{osti_1543566,
title = {Pressure induced short-range structural changes in supercooled liquid Ge2Sb2Te5},
author = {Qiao, Chong and Guo, Y. R. and Wang, J. J. and Shen, H. and Wang, S. Y. and Zheng, Y. X. and Zhang, R. J. and Chen, L. Y. and Wang, C. Z. and Ho, K. M.},
abstractNote = {Phase-change material such as Ge2Sb2Te5 is usually utilized to store data due to the pronounced contrast in optical and electrical properties between crystalline and amorphous phases. As the density differs in the two phases, it is necessary to explore the influence of pressure on the structures of Ge2Sb2Te5, especially for the supercooled liquid which is an inevitable state in the formation of the two phases. The short-range structures in supercooled liquid Ge2Sb2Te5 under compression have been investigated by using ab initio molecular dynamics simulation. The supercooled liquid eventually changes to a solid with an increase in pressure. During the process, tetrahedrons decrease slightly, revealing that tetrahedral structures are insensitive to the pressure. Octahedrons increase as the pressure is less than 3.7 GPa and then decrease, suggesting that a moderate pressure can promote the formation of octahedrons. The body-centered-cubic, face-centered-cubic and hexagonal closed-packed structures are observed at 9.9 GPa and then increase gradually. Additionally, it is noticed that Sb- and Te-centered clusters prefer Ge-centered clusters to forming the high-coordinated short-range structures during the compression process. Our research make us aware of the effects of pressure on short-range structures in supercooled liquid, which is of great importance in the application of phase-change materials.},
doi = {10.1016/j.jnoncrysol.2018.10.028},
journal = {Journal of Non-Crystalline Solids},
issn = {0022-3093},
number = C,
volume = 503-504,
place = {United States},
year = {2019},
month = {1}
}