Local structure origin of ultrafast crystallization driven by high-fidelity octahedral clusters in amorphous Sc0.2Sb2Te3

被引：28

作者：

Qiao, Chong ^{[1
,2
]}

Guo, Y. R. ^{[1
,2
]}

Wang, S. Y. ^{[1
,2
,3
]}

Xu, Ming ^{[4
]}

Miao, Xiangshui ^{[4
]}

Wang, C. Z. ^{[5
,6
]}

Ho, K. M. ^{[5
,6
]}

机构：

[1] Fudan Univ, Shanghai Ultraprecis Opt Mfg Engn, Shanghai 200433, Peoples R China

[2] Fudan Univ, Dept Opt Sci & Engn, Shanghai 200433, Peoples R China

[3] Key Lab Informat Sci Electromagnet Waves MoE, Shanghai 200433, Peoples R China

[4] Huazhong Univ Sci & Technol, Sch Opt & Elect Informat, Wuhan Natl Res Ctr Optoelect, Wuhan 430074, Hubei, Peoples R China

[5] Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA

[6] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA

来源：

APPLIED PHYSICS LETTERS | 2019年 / 114卷 / 07期

基金：

中国国家自然科学基金;

关键词：

PHASE-CHANGE MATERIALS;

D O I：

10.1063/1.5085502

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

Phase-change material Sc0.2Sb2Te3 (SST) can remarkably boost the writing speed of memory devices due to the extremely fast crystallization. It was demonstrated that the fast crystallization is because Sc stabilizes the 4-fold rings which act as precursors of nuclei in the amorphous phase. In this work, by using first-principles molecular dynamics simulations, we studied the local structures in the liquid and amorphous SST at various temperatures. The results 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. Published under license by AIP Publishing.

引用

页数：4

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