Journal
JOURNAL OF PHYSICS-CONDENSED MATTER
Volume 21, Issue 45, Pages -Publisher
IOP PUBLISHING LTD
DOI: 10.1088/0953-8984/21/45/455401
Keywords
-
Categories
Funding
- US Army Research Office (ARO) [ARO-W911NF-07-1-0490]
- DARPA SAM II through ONR [N00014-06-1-0490]
Ask authors/readers for more resources
In this paper, we employ an ab initio density functional theory calculation to investigate the elastic stability of face-centered cubic Au under hydrostatic deformation. We identify the elastic stiffness constant B-ijkl as the coefficient in the stress-strain relation for an arbitrary deformed state, and use it to test the stability condition. We show that this criterion bears the same physics as that proposed earlier by Frenkel and Orowan and agrees with the Born-Hill criterion. The results from those two approaches agree well with each other. We show that the stability limit, or instability, of the perfect Au crystal under hydrostatic expansion is not associated with the bulk stiffness modulus as predicted in the previous work; rather it is caused by a shear instability associated with the vanishing rhombohedral shear stiffness modulus. The deviation of the deformation mode from the primary hydrostatic loading path signals a bifurcation or symmetry breaking in the ideal crystal. The corresponding ideal hydrostatic strength for Au is 19.2 GPa at the Lagrangian expansion strain of similar to 0.06. In the case of compression, Au remains stable over the entire pressure range in our calculation.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available