Publication detail

Effect of normal stress on the ideal shear strength in covalent crystals

UMENO, Y. ČERNÝ, M.

Original Title

Effect of normal stress on the ideal shear strength in covalent crystals

Type

journal article in Web of Science

Language

English

Original Abstract

Critical shear stress under the superimposed hydrostatic and uniaxial normal stress conditions of C, Si, Ge, and SiC is evaluated by ab initio density functional theory calculations to investigate the response of ideal shear strength (ISS) to superimposed normal stresses in covalent crystals. We find a substantial difference in the responses of ISS to normal stress among the covalent crystals examined; e.g., hydrostatic compression increases the ISS of C but decreases that of Si, Ge, and SiC. The ISS is mostly a highly nonlinear and anisotropic function of normal stress. The results thus indicate that normal stresses can significantly affect the critical shear stress, which is crucial to interpreting experimental observations of crystal deformation, e.g., dislocation nucleation in nanoindentation.

Keywords

shear strength, normal stress, ab initio

Authors

UMENO, Y.; ČERNÝ, M.

RIV year

2008

Released

10. 3. 2008

Publisher

AMER PHYSICAL SOC

Location

ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA

ISBN

1098-0121

Periodical

PHYSICAL REVIEW B

Year of study

77

Number

3

State

United States of America

Pages from

100101

Pages to

100101-4

Pages count

4