Crystallization of Ge2Sb2Te5 under high hydrostatic pressures: Differences in nanoscale atomic ordering in as-deposited and pressure-induced amorphous phases

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F21%3A39918018" target="_blank" >RIV/00216275:25310/21:39918018 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S092583882101389X?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S092583882101389X?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jallcom.2021.159980" target="_blank" >10.1016/j.jallcom.2021.159980</a>

Result language

angličtina

Original language name

Crystallization of Ge2Sb2Te5 under high hydrostatic pressures: Differences in nanoscale atomic ordering in as-deposited and pressure-induced amorphous phases

Original language description

The crystallization process acts as a bottleneck to the development of phase-change memory devices. Here, we compare the crystallization of as-deposited and pressure-induced amorphous phases of Ge2Sb2Te5 under hydrostatic pressures up to 8.5 GPa. The as-deposited phase fully converts to a stressed metastable cubic phase (at ca. 135 degrees C) at pressures below 3 GPa and remains cubic up to the maximum temperature used (240 degrees C). At higher pressures, the as-deposited phase partially crystallizes directly into the stable hexagonal phase at a significantly lower temperature (110 degrees C), however a significant volume fraction of the amorphous phase remains even for temperatures as high as 240 degrees C. The intensities of the Bragg diffraction peaks dramatically decrease with increasing pressure, further underscoring the suppression of crystal growth. In stark contrast, the pressure-induced amorphous phase- due to memory effects originating from the crystalline phase - crystallizes at ambient conditions at a lower temperature than its as-deposited counterpart. Furthermore, the pressure-induced amorphous phase also fully transforms directly into the hexagonal modification at pressures up to ca. 5 GPa. At higher pressure (8.5 GPa), an orthorhombic phase is formed. Different from the as-deposited phase, the crystallization temperature of pressure-induced amorphous Ge2Sb2Te5 increases with pressure. The results reported here demonstrate that differences in nanoscale ordering in as-deposited (statistically ordered) and pressure-induced (chemically ordered) amorphous phases dramatically influence crystallization and will serve as a guideline for insightful development of phase-change devices. (C) 2021 The Author(s). Published by Elsevier B.V.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

20501 - Materials engineering

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Alloys and Compounds

ISSN

0925-8388

e-ISSN

—

Volume of the periodical

874

Issue of the periodical within the volume

September

Country of publishing house

CH - SWITZERLAND

Number of pages

7

Pages from-to

159980

UT code for WoS article

000653093100001

EID of the result in the Scopus database

2-s2.0-85104631304