Publication Date

2-20-2019

Department

Ames Laboratory; Physics and Astronomy

Campus Units

Ames Laboratory, Physics and Astronomy

Report Number

IS-J 9897

DOI

10.1063/1.5085502

Journal Title

Applied Physics Letters

Volume Number

114

Issue Number

7

First Page

071901

Abstract

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.

DOE Contract Number(s)

AC02-07CH11358

Language

en

Publisher

Iowa State University Digital Repository, Ames IA (United States)

Available for download on Thursday, February 20, 2020

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