Phonon instabilities and the ideal strength of aluminum

We have calculated the phonon spectra of aluminum as a function of strain using density functional perturbation theory for , , and uniaxial tension, as well as relaxed [111] shear. In all four cases, phonon instabilities occur at points away from the center of the Brillouin zone and intrude before t...

Full description

Saved in:
Bibliographic Details
Published in:Physical review letters 2003-09, Vol.91 (13), p.135501-135501
Main Authors: Clatterbuck, D M, Krenn, C R, Cohen, Marvin L, Morris, Jr, J W
Format: Article
Language:English
Subjects:
ACOUSTICS
ALUMINIUM
BRILLOUIN ZONES
CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRYSTALLOGRAPHY
FUNCTIONALS
PERTURBATION THEORY
PHONONS
PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
SHEAR
SPECTRA
STABILITY
STRAINS
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We have calculated the phonon spectra of aluminum as a function of strain using density functional perturbation theory for , , and uniaxial tension, as well as relaxed [111] shear. In all four cases, phonon instabilities occur at points away from the center of the Brillouin zone and intrude before the material becomes unstable according to elastic stability criteria. This is the first time the ideal strength of a metal has been shown to be dictated by instabilities in the acoustic phonon spectra. We go on to describe the crystallography of the unstable modes, all of which are shear in character. This work further suggests that shear failure is an inherent property of aluminum even in an initially dislocation-free perfect crystal.
ISSN:0031-9007
1079-7114
DOI:10.1103/PhysRevLett.91.135501