Interpretation of the Lattice-strains Measured Under Non-hydrostatic Pressure

Abstract

The equations for the lattice strains produced by non-hydrostatic compression of the specimen are presented for all seven crystal systems in a form suitable for the analysis of experimental data. Examples of cubic (FeO and bcc iron) and hexagonal (hcp iron) systems are given to demonstrate that the analyses of the data give the estimates of single crystal elastic constants under high pressures. As the lattice strains can be measured at high pressures up to a few megabars using a diamond anvil cell, this approach offers an unique method of estimating the elastic constants at such high pressures. Further, this is the only method of estimating elastic constants of a phase stabilized under pressure. The article also discusses some other interesting specimen-material properties that can be derived at such high pressures. [Non-hydrostatic compression, Uniaxial stress component, Elastic constants, High pressure]. © 1998, The Japan Society of High Pressure Science and Technology. All rights reserved.