| Title: |
Atomistic Study of the Configurational Entropy and the Fragility of Supercooled Liquid GeTe |
| Authors: |
Chen Y.; Campi D.; Bernasconi M.; Mazzarello R. |
| Contributors: |
Chen, Y; Campi, D; Bernasconi, M; Mazzarello, R |
| Publisher Information: |
Wiley-VCH Verlag GmbH & Co. KGaA; DE |
| Publication Year: |
2024 |
| Collection: |
Università degli Studi di Milano-Bicocca: BOA (Bicocca Open Archive) |
| Subject Terms: |
configurational entropy; fragility; phase-change material; potential energy landscape; supercooled liquid; Settore PHYS-03/A - Fisica sperimentale della materia e applicazioni; Settore PHYS-04/A - Fisica teorica della materia; modelli; metodi matematici e applicazioni |
| Description: |
Phase-change materials (PCMs) are an important family of alloys employed in non-volatile memories and neuromorphic devices. These devices exploit the ability of PCMs to undergo rapid transitions between amorphous and crystalline phases at moderately high temperature. At ambient conditions, both phases are stable. These properties imply a very strong temperature dependence of the crystallization kinetics, which has been attributed to the high fragility of the supercooled liquid phase. In this work, the fragility index of GeTe, an important PCM, is extracted from a computational exploration of the potential energy landscape of the system by molecular dynamics simulations. For this purpose, a neural-network potential is used to describe the interatomic interactions, which enables the evaluation of the configurational entropy in the deeply supercooled regime. The viscosity and the relaxation times are also calculated in the same temperature range. Finally, the Adam-Gibbs relation is used to extrapolate the data to low temperatures and estimate the glass transition temperature and the fragility index. The latter quantity turns out to be of the order of 135–140, which shows that liquid GeTe is a highly fragile system. |
| Document Type: |
article in journal/newspaper |
| File Description: |
STAMPA |
| Language: |
English |
| Relation: |
info:eu-repo/semantics/altIdentifier/wos/WOS:001158233700001; volume:34; issue:22 (May 29, 2024); firstpage:1; lastpage:8; numberofpages:8; journal:ADVANCED FUNCTIONAL MATERIALS; https://hdl.handle.net/10281/483459 |
| DOI: |
10.1002/adfm.202314264 |
| Availability: |
https://hdl.handle.net/10281/483459; https://doi.org/10.1002/adfm.202314264 |
| Rights: |
info:eu-repo/semantics/openAccess ; license:Tutti i diritti riservati ; license:Creative Commons ; license uri:iris.PRI01 ; license uri:http://creativecommons.org/licenses/by/4.0/ |
| Accession Number: |
edsbas.F22CD0FB |
| Database: |
BASE |