Open AccessDisorder Control in Crystalline GeSb 2 Te 4 Using High Pressure
Author(s) -
Xu Ming,
Zhang Wei,
Mazzarello Riccardo,
Wuttig Matthias
Publication year - 2015
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201500117
Subject(s) - materials science , amorphous solid , electron localization function , condensed matter physics , chemical physics , electrical resistivity and conductivity , lattice (music) , molecular dynamics , phase transition , phase (matter) , ambient pressure , electronic structure , ab initio , electron , crystallography , thermodynamics , computational chemistry , chemistry , physics , organic chemistry , quantum mechanics , acoustics
Electronic phase‐change memory devices take advantage of the different resistivity of two states, amorphous and crystalline, and the swift transitions between them in active phase‐change materials (PCMs). In addition to these two distinct phases, multiple resistive states can be obtained by tuning the atomic disorder in the crystalline phase with heat treatment, because the disorder can lead to the localization of the electronic states and, thus, hamper the electron transport. The goal of this work is to achieve and explore multiple disordered configurations in PCMs by applying high pressure. Large‐scale ab initio molecular dynamics simulations demonstrate that pressure can lower the energy barrier for the antisite migration in crystalline PCMs. The accumulation of these antisite atoms largely increases the compositional disorder, adding localized electronic states near the conduction band. The disorder‐induced electron localization triggered by pressure is a novel way to modulate the properties of materials. Furthermore, the random distortion of the lattice induced by the compositional disorder provides a new mechanism that contributes to the amorphization of crystalline PCMs at high pressure.