Displacement field and elastic constants in nonideal crystals

Displacement field and elastic constants in nonideal crystals

In this work a periodic crystal with point defects is described in the framework of linear-response theory for broken-symmetry states using correlation functions and Zwanzig-Mori equations. The main results are microscopic expressions for the elastic constants and for the coarse-grained density, point-defect density, and displacement field, which are valid in real crystals, where vacancies and ...

Elastic Constants and Displacement Fields in Crystals with Point Defects

Apparent elastic constants of cubic crystals and their pressure derivatives

Expressions for the pressure-dependent apparent elastic constants of cubic crystals are derived in terms of their original secondand third-order elastic constants. New expressions are obtained for the apparent compliances and their pressure derivatives. Results are shown to be in agreement with those based on the apparent elastic moduli. ( 1998 Elsevier Science Ltd. All rights reserved.

Elastic Constants of Nematic Liquid Crystals of Uniaxial Symmetry

We study in detail the influence of molecular interactions on the Frank elastic constants of uniaxial nematic liquid crystals composed of molecules of cylindrical symmetry. A brief summary of the status of theoretical development for the elastic constants of nematics is presented. Considering a pair potential having both repulsive and attractive parts numerical calculations are reported for thr...

Statistical Theory of Elastic Constants of Cholesteric Liquid Crystals

A statistical theory of cholesteric liquid crystals composed of short rigid biaxial molecules is presented. It is derived in the thermodynamic limit at a small density and a small twist. The uniaxial (biaxial) cholesteric phase is regarded as a distorted form of the uniaxial (biaxial) nematic phase. The chirality of the interactions and the implementation of the inversion to the rotation matrix...