Local structure origin of ultrafast crystallization driven by high-fidelity octahedral clusters in amorphous Sc0.2Sb2Te3
- Fudan Univ., Shanghai (China)
- Fudan Univ., Shanghai (China); Key Lab. for Information Science of Electromagnetic Waves (MoE), Shanghai (China)
- Huazhong Univ. of Science and Technology, Wuhan (China)
- Ames Lab. and Iowa State Univ., Ames, IA (United States)
Phase-change material Sc0.2Sb2Te3 (SST) can remarkably boost the writing speed of memory devices due to the extremely fast crystallization. It was reflected that the fast crystallization is because Sc stabilizes the 4-fold rings which act as precursors of nuclei in the amorphous phase. Here, by using first-principles molecular dynamics simulations, we studied the local structures in the liquid and amorphous SST at various temperatures. The findings reveal that Sc-centered configurations are almost in the form of stable octahedral clusters, which enhances the local order of the amorphous phase. Different from Sb- and Te-centered clusters which have lower coordination numbers, Sc-centered clusters are mainly in high-coordinated octahedral structures. These Sc-centered octahedral clusters present a high stability in supercooled liquid and amorphous states, remarkably reducing the incubation time of nucleation and speeding up the crystallization. Our study reveals the role of Sc atoms in the liquid and amorphous structure, paving the way for the application of Sc-based phase-change memory.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Iowa State Univ., Ames, IA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; National Science Foundation (NSF)
- Grant/Contract Number:
- AC02-07CH11358
- OSTI ID:
- 1543901
- Journal Information:
- Applied Physics Letters, Vol. 114, Issue 7; ISSN 0003-6951
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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