Revisit of the relationship between the elastic properties and sound velocities at high pressures

The second-order elastic constants and stress-strain coefficients are defined, respectively, as the second derivatives of the total energy and the first derivative of the stress with respect to strain. Since the Lagrangian and infinitesimal strain are commonly used in the two definitions above, the...

Full description

Saved in:
Bibliographic Details
Published in:Journal of applied physics 2014-09, Vol.116 (10)
Main Authors: Wang, Chenju, Xiang, Shikai, Gu, Jianbing, Kuang, Xiaoyu, Yu, Yin, Yan, Xiaozhen, Chen, Haiyan
Format: Article
Language:English
Subjects:
Applied physics
CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
CUBIC LATTICES
Elastic properties
Elastic waves
ELASTICITY
Initial stresses
LAGRANGIAN FUNCTION
Material properties
MATERIALS SCIENCE
Mathematical analysis
RHENIUM
Sound
SOUND WAVES
Strain
STRAINS
Stress-strain relationships
STRESSES
TANTALUM
WAVE EQUATIONS
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The second-order elastic constants and stress-strain coefficients are defined, respectively, as the second derivatives of the total energy and the first derivative of the stress with respect to strain. Since the Lagrangian and infinitesimal strain are commonly used in the two definitions above, the second-order elastic constants and stress-strain coefficients are separated into two categories, respectively. In general, any of the four physical quantities is employed to characterize the elastic properties of materials without differentiation. Nevertheless, differences may exist among them at non-zero pressures, especially high pressures. Having explored the confusing issue systemically in the present work, we find that the four quantities are indeed different from each other at high pressures and these differences depend on the initial stress applied on materials. Moreover, the various relations between the four quantities depicting elastic properties of materials and high-pressure sound velocities are also derived from the elastic wave equations. As examples, we calculated the high-pressure sound velocities of cubic tantalum and hexagonal rhenium using these nexus. The excellent agreement of our results with available experimental data suggests the general applicability of the relations.
ISSN:0021-8979
1089-7550
DOI:10.1063/1.4895495