Regular Article

Interface effect and stress effect on Ge₂Sb₂Te₅/Sb superlattice-like thin films

¹ School of Mathematics and Physics, Jiangsu University of Technology, Changzhou 213001, China
² State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China

^a e-mail: zhengphy@163.com
^b e-mail: pcram@jsut.edu.cn

Received: 24 October 2016
Revised: 21 January 2017
Accepted: 6 March 2017
Published online: 12 April 2017

Abstract

Ge₂Sb₂Te₅ superlattice-like thin films show great potential for phase-change memory applications. Improvement of the thermal properties of Ge₂Sb₂Te₅ is believed to be related to the Ge₂Sb₂Te₅/Sb interface. The stress effect and interface effect on Ge₂Sb₂Te₅ manifest in structural changes that are observed via X-ray diffraction and Raman spectroscopy experiments. The structure changes from corner-sharing GeTe_4-nGe_n (n = 0) in single-layered Ge₂Sb₂Te₅ to GeTe_4-nGe_n (n = 1, 2, 3) tetrahedra in the superlattice-like thin films that are observed. As a result, Ge₂Sb₂Te₅ prefers the hexagonal structure rather than the face-centred cubic structure during heating.