In situ characterization of vacancy ordering in Ge-Sb-Te phase-change memory alloys  

作　　者：Ting-Ting Jiang Xu-Dong Wang Jiang-Jing Wang Han-Yi Zhang Lu Lu Chunlin Jia Matthias Wuttig Riccardo Mazzarello Wei Zhang En Ma 

机构地区：[1]Center for Alloy Innovation and Design(CAID),State Key Laboratory for Mechanical Behavior of Materials,Xi'an Jiaotong University,Xi'an 710049,China [2]Institute of Physics IA,RWTH Aachen University,Aachen 52074,Germany [3]The School of Microelectronics,State Key Laboratory for Mechanical Behavior of Materials,Xi'an Jiaotong,University,Xi'an 710049,China [4]JARA-FIT and JARA-HPC,RWTH Aachen University,Aachen 52056,Germany [5]Peter Grünberg Institute(PGI 10),Forschungszentrum Jülich GmbH,Jülich 52425,Germany [6]Department of Physics,Sapienza University of Rome,Rome 00185,Italy

出　　处：《Fundamental Research》2024年第5期1235-1242,共8页自然科学基础研究（英文版）

基　　金：support of National Natural Science Foundation of China(61774123);support of National Natural Science Foundation of China(52150710545);support of their work at CAID.J.-J.W.and M.W.acknowledges financial support from Alexander von Humboldt Foundation;funding from Deutsche Forschungsgemeinschaft within SFB 917“Nanoswitches”;support of 111 Project 2.0(BP2018008);the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies of Xi'an Jiaotong University;provided by the HPC platform of Xi'an Jiaotong University and the Hefei Advanced Computing Center,and the National Supercomputing Center in Xi'an.

摘　　要：Tailoring the degree of structural disorder in Ge-Sb-Te alloys is important for the development of non-volatile phase-change memory and neuro-inspired computing.Upon crystallization from the amorphous phase,these alloys form a cubic rocksalt-like structure with a high content of intrinsic vacancies.Further thermal annealing results in a gradual structural transition towards a layered structure and an insulator-to-metal transition.In this work,we elucidate the atomic-level details of the structural transition in crystalline GeSb_(2)Te_(4) by in situ high-resolution transmission electron microscopy experiments and ab initio density functional theory calculations,providing a comprehensive real-time and real-space view of the vacancy ordering process.We also discuss the impact of vacancy ordering on altering the electronic and optical properties of GeSb_(2)Te_(4),which is relevant to multilevel storage applications.The phase evolution paths in Ge-Sb-Te alloys and Sb_(2)Te_(3)are illustrated using a summary diagram,which serves as a guide for designing phase-change memory devices.

关 键 词：Phase-change materials Vacancy ordering Structural transition Metavalent bondingin situ TEM 

分 类 号：TG146[一般工业技术—材料科学与工程]