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 allo...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.展开更多
基金support of National Natural Science Foundation of China(61774123)support of National Natural Science Foundation of China(52150710545)+4 种基金support of their work at CAID.J.-J.W.and M.W.acknowledges financial support from Alexander von Humboldt Foundationfunding 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 Universityprovided by the HPC platform of Xi'an Jiaotong University and the Hefei Advanced Computing Center,and the National Supercomputing Center in Xi'an.
文摘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.
