Indexed by: Journal paper

First Author: 冯金龙

Correspondence Author: 缪向水

Co-author: 徐明,程晓敏,林琪,王校杰,徐萌

Journal: Applied Physics Letters

Affiliation of Author(s): 华中科技大学

Discipline: Engineering

First-Level Discipline: Electronic Science And Technology

Document Type: J

Volume: 112

Issue: 7

Page Number: 071902

Key Words: Phase transitions, Chalcogenides, Phase change memories, Memory device

DOI number: 10.1063/1.5006718

Date of Publication: 4314-03-01

Abstract: Phase change memory (PCM) is an important candidate for future memory devices. The crystalline phase of PCM materials contains abundant intrinsic vacancies, which plays an important role in the rapid phase transition upon memory switching. However, few experimental efforts have been invested to study these invisible entities. In this work, Au dopants are alloyed into the crystalline GeTe to fill the intrinsic Ge vacancies so that the role of these vacancies in the amorphization of GeTe can be indirectly studied. As a result, the reduction of Ge vacancies induced by Au dopants hampers the amorphization of GeTe as the activation energy of this process becomes higher. This is because the vacancy-interrupted lattice can be “repaired” by Au dopants with the recovery of bond connectivity. Our results demonstrate the importance of vacancies in the phase transition of chalcogenides, and we employ the percolation theory to explain the impact of these intrinsic defects on this vacancy-ridden crystal quantitatively. Specifically, the threshold of amorphization increases with the decrease in vacancies. The understanding of the vacancy effect sheds light on the long-standing puzzle of the mechanism of ultra-fast phase transition in PCMs. It also paves the way for designing low-power-consumption electronic devices by reducing the threshold of amorphization in chalcogenides.

Links to published journals: https://pubs.aip.org/aip/apl/article-abstract/112/7/071902/36269/Gold-fillings-unravel-the-vacancy-role-in-the?redirectedFrom=fulltext