title: Aluminum-centered tetrahedron-octahedron transition in advancing Al-Sb-Te phase change properties.
abstract: Group IIIA elements, Al, Ga, or In, etc., doped Sb-Te materials have proven good phase change properties, especially the superior data retention ability over popular Ge2Sb2Te5, while their phase transition mechanisms are rarely investigated. In this paper, aiming at the phase transition of Al-Sb-Te materials, we reveal a dominant rule of local structure changes around the Al atoms based on ab initio simulations and nuclear magnetic resonance evidences. By comparing the local chemical environments around Al atoms in respective amorphous and crystalline Al-Sb-Te phases, we believe that Al-centered motifs undergo reversible tetrahedron-octahedron reconfigurations in phase transition process. Such Al-centered local structure rearrangements significantly enhance thermal stability of amorphous phase compared to that of undoped Sb-Te materials, and facilitate a low-energy amorphization due to the weak links among Al-centered and Sb-centered octahedrons. Our studies may provide a useful reference to further understand the underlying physics and optimize performances of all IIIA metal doped Sb-Te phase change materials, prompting the development of NOR/NAND Flash-like phase change memory technology.
authors.affiliation: 1] State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China [2] Graduate University of the Chinese Academy of Sciences, Beijing 100080, China.
authors.forename: Mengjiao
authors.initials: M
authors.lastname: Xia
authors.affiliation: 1] State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China [2] Graduate University of the Chinese Academy of Sciences, Beijing 100080, China.
authors.forename: Keyuan
authors.initials: K
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Rao
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China.
authors.forename: Xianbin
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Liangcai
authors.initials: L
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Zhitang
authors.initials: Z
authors.lastname: Song