Saved in:
Bibliographic Details
Main Authors: Rovaris, Fabrizio, Marzegalli, Anna, Montalenti, Francesco, Scalise, Emilio
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2408.12358
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908867436216320
author Rovaris, Fabrizio
Marzegalli, Anna
Montalenti, Francesco
Scalise, Emilio
author_facet Rovaris, Fabrizio
Marzegalli, Anna
Montalenti, Francesco
Scalise, Emilio
contents Silicon exhibits several metastable allotropes which recently attracted attention in the quest for materials with superior (e.g. optical) properties, compatible with Si technology. In this work we shed light on the atomic-scale mechanisms leading to phase transformations in Si under pressure. To do so, we synergically exploit different state-of-the-art approaches. In particular, we use the advanced GAP interatomic potential both in NPT molecular dynamics simulations and in solid-state nudged elastic band calculations, validating our predictions with ab initio DFT calculations. We provide a link between evidence reported in experimental nanoindentation literature and simulation results. Particular attention is dedicated to the investigation of atomistic transition paths allowing for the transformation between BC8/R8 phases to the hd one under pure annealing. In this case we show a direct simulation of the local nucleation of the hexagonal phase in a BC8/R8 matrix and its corresponding atomic-scale mechanism extracted by the use of SS-NEB. We extend our study investigating the effect of pressure on the nucleation barrier, providing an argument for explaining the heterogeneous nucleation of the hd phase observed in experiments reported in the literature.
format Preprint
id arxiv_https___arxiv_org_abs_2408_12358
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Unraveling the Atomic-Scale Pathways Driving Pressure-Induced Phase Transitions in Silicon
Rovaris, Fabrizio
Marzegalli, Anna
Montalenti, Francesco
Scalise, Emilio
Materials Science
Computational Physics
Silicon exhibits several metastable allotropes which recently attracted attention in the quest for materials with superior (e.g. optical) properties, compatible with Si technology. In this work we shed light on the atomic-scale mechanisms leading to phase transformations in Si under pressure. To do so, we synergically exploit different state-of-the-art approaches. In particular, we use the advanced GAP interatomic potential both in NPT molecular dynamics simulations and in solid-state nudged elastic band calculations, validating our predictions with ab initio DFT calculations. We provide a link between evidence reported in experimental nanoindentation literature and simulation results. Particular attention is dedicated to the investigation of atomistic transition paths allowing for the transformation between BC8/R8 phases to the hd one under pure annealing. In this case we show a direct simulation of the local nucleation of the hexagonal phase in a BC8/R8 matrix and its corresponding atomic-scale mechanism extracted by the use of SS-NEB. We extend our study investigating the effect of pressure on the nucleation barrier, providing an argument for explaining the heterogeneous nucleation of the hd phase observed in experiments reported in the literature.
title Unraveling the Atomic-Scale Pathways Driving Pressure-Induced Phase Transitions in Silicon
topic Materials Science
Computational Physics
url https://arxiv.org/abs/2408.12358