CaltechAUTHORS
Published December 2018 | Version Supplemental Material
Journal Article Open

Mechanical softening of thermoelectric semiconductor Mg_2Si from nanotwinning

Creators

  • 1. ROR icon Wuhan University of Technology
  • 2. ROR icon Northwestern University
  • 3. ROR icon University of Nevada Reno
  • 4. ROR icon South Ural State University
  • 5. ROR icon California Institute of Technology

Abstract

Nanotwinning exhibits strengthening effects in many metals, semiconductors, and ceramics. However, we show from ab-initio calculations that nanotwins significantly decrease the strength of thermoelectric semiconductor Mg_2Si. The theoretical shear strength of nanotwinned Mg_2Si is found to be 0.93 GPa, much lower than that (6.88 GPa) of flawless Mg_2Si. Stretching the Mg-Si bond under deformation leads to the structural softening and failure of flawless Mg_2Si. While in nanotwinned Mg_2Si, the Mg-Si bond at the twin boundary (TB) is expanded to accommodate the structural misfit, weakening the TB rigidity and leading to the low ideal shear strength.

Additional Information

© 2018 Acta Materialia Inc. Published by Elsevier Ltd. Received 24 April 2018, Revised 13 July 2018, Accepted 1 August 2018, Available online 9 August 2018. This work is partially supported by NSF of China under No. 51772231, the 111 Project of China under Project no. B07040. Q.A. was supported by the National Science Foundation CMMI program under grant no. 1727428. S.M. was thankful for the support by Act 211 Government of the Russian Federation, under No. 02.A03.21.0011 and by the Supercomputer Simulation Laboratory of South Ural State University [26].

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Supplemental Material - 1-s2.0-S1359646218304767-mmc1.docx

Supplemental Material - 1-s2.0-S1359646218304767-mmc2.zip

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Additional details

Additional titles

Alternative title
Mechanical softening of thermoelectric semiconductor Mg2 Si from nanotwinning

Identifiers

Eprint ID
88679
Resolver ID
CaltechAUTHORS:20180809-080526657

Funding

National Natural Science Foundation of China
51772231
111 Project of China
B07040
NSF
CMMI-1727428

Dates

Created
2018-08-09
Created from EPrint's datestamp field
Updated
2021-11-16
Created from EPrint's last_modified field

Caltech Custom Metadata

Other Numbering System Name
WAG
Other Numbering System Identifier
1299