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Title: In situ observation of shear-driven amorphization in silicon crystals

Abstract

Amorphous materials have attracted great interest in the scientific and technological fields. An amorphous solid usually forms under the externally driven conditions of melt-quenching, irradiation and severe mechanical deformation. However, its dynamic formation process remains elusive. Here we report the in situ atomic-scale observation of dynamic amorphization processes during mechanical straining of nanoscale silicon crystals by high resolution transmission electron microscopy (HRTEM). We observe the shear-driven amorphization (SDA) occurring in a dominant shear band. The SDA involves a sequence of processes starting with the shear-induced diamond-cubic to diamond-hexagonal phase transition that is followed by dislocation nucleation and accumulation in the newly formed phase, leading to the formation of amorphous silicon. The SDA formation through diamond-hexagonal phase is rationalized by its structural conformity with the order in the paracrystalline amorphous silicon, which maybe widely applied to diamond-cubic materials. Besides, the activation of SDA is orientation-dependent through the competition between full dislocation nucleation and partial gliding.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
1340797
Report Number(s):
PNNL-SA-114344
Journal ID: ISSN 1748-3387; 48379; KP1704020
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Nature Nanotechnology
Additional Journal Information:
Journal Volume: 11; Journal Issue: 10; Journal ID: ISSN 1748-3387
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
Amorphization; silicon; crystals; in-situ; nanoscale; high resolution transmission electron microscopy; Environmental Molecular Sciences Laboratory

Citation Formats

He, Yang, Zhong, Li, Fan, Feifei, Wang, Chongmin, Zhu, Ting, and Mao, Scott X. In situ observation of shear-driven amorphization in silicon crystals. United States: N. p., 2016. Web. doi:10.1038/NNANO.2016.166.
He, Yang, Zhong, Li, Fan, Feifei, Wang, Chongmin, Zhu, Ting, & Mao, Scott X. In situ observation of shear-driven amorphization in silicon crystals. United States. https://doi.org/10.1038/NNANO.2016.166
He, Yang, Zhong, Li, Fan, Feifei, Wang, Chongmin, Zhu, Ting, and Mao, Scott X. 2016. "In situ observation of shear-driven amorphization in silicon crystals". United States. https://doi.org/10.1038/NNANO.2016.166.
@article{osti_1340797,
title = {In situ observation of shear-driven amorphization in silicon crystals},
author = {He, Yang and Zhong, Li and Fan, Feifei and Wang, Chongmin and Zhu, Ting and Mao, Scott X.},
abstractNote = {Amorphous materials have attracted great interest in the scientific and technological fields. An amorphous solid usually forms under the externally driven conditions of melt-quenching, irradiation and severe mechanical deformation. However, its dynamic formation process remains elusive. Here we report the in situ atomic-scale observation of dynamic amorphization processes during mechanical straining of nanoscale silicon crystals by high resolution transmission electron microscopy (HRTEM). We observe the shear-driven amorphization (SDA) occurring in a dominant shear band. The SDA involves a sequence of processes starting with the shear-induced diamond-cubic to diamond-hexagonal phase transition that is followed by dislocation nucleation and accumulation in the newly formed phase, leading to the formation of amorphous silicon. The SDA formation through diamond-hexagonal phase is rationalized by its structural conformity with the order in the paracrystalline amorphous silicon, which maybe widely applied to diamond-cubic materials. Besides, the activation of SDA is orientation-dependent through the competition between full dislocation nucleation and partial gliding.},
doi = {10.1038/NNANO.2016.166},
url = {https://www.osti.gov/biblio/1340797}, journal = {Nature Nanotechnology},
issn = {1748-3387},
number = 10,
volume = 11,
place = {United States},
year = {Mon Sep 19 00:00:00 EDT 2016},
month = {Mon Sep 19 00:00:00 EDT 2016}
}