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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

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

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název periodika

Journal of Alloys and Compounds

ISSN

0925-8388

e-ISSN

—

Svazek periodika

874

Číslo periodika v rámci svazku

September

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

7

Strana od-do

159980

Kód UT WoS článku

000653093100001

EID výsledku v databázi Scopus

2-s2.0-85104631304