A Phase-Change Mechanism of GST-SL Based Superlattices upon Sb Flipping

Teng Sun; Furong Liu; Jicheng Guo; Gang Han; Yongzhi Zhang

doi:10.3390/ma14020360

A Phase-Change Mechanism of GST-SL Based Superlattices upon Sb Flipping

Materials (Basel). 2021 Jan 13;14(2):360. doi: 10.3390/ma14020360.

Authors

Teng Sun^{1

2

3}, Furong Liu^{1

2

3}, Jicheng Guo^{1

2

3}, Gang Han^{1

2

3}, Yongzhi Zhang^{1

2

3}

Affiliations

¹ Key Laboratory of Trans-Scale Laser Manufacturing Technology, Beijing University of Technology, Ministry of Education, 100 Ping Leyuan, Chaoyang District, Beijing 100124, China.
² Beijing Engineering Research Center of Laser Technology, Beijing University of Technology, 100 Ping Leyuan, Chaoyang District, Beijing 100124, China.
³ Institute of Laser Engineering, Faculty of Materials and Manufacturing, Beijing University of Technology, 100 Ping Leyuan, Chaoyang District, Beijing 100124, China.

Abstract

Reversible phase-change behaviors of Ge-Sb-Te based superlattices (GST-SL) were studied by ab initio molecular dynamics (AIMD) simulations based on three models containing Ge/Sb intermixing, namely the Petrov-mix, Ferro-mix, and Kooi-mix models. The flipping behavior of Sb atoms was found in all the three GST-SL models in the melting process. Among them the Kooi-mix model exhibited the best stability, and the analyses of bond length distribution and electron localization function provided a better explanation on the phase transition of GST-SL. Finally, we proposed a fast switching model for GST-SL based on Sb flipping.

Keywords: AIMD simulation; GST-SL; PCMs; flipping; superlattices.