Lattice-Dynamics Approach to the Theory of Elastic Dielectrics with Polarization Gradient

1970/04/15 by A. Askar, Attila Aşkar, P. C. Y. Lee +2
Engineering · Materials Science · #Acoustic Wave Resonator Technologies #Ferroelectric and Piezoelectric Materials #Material Dynamics and Properties

paper · doi:10.1103/physrevb.1.3525

openalex publication_date 1970/04/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/26

Abstract

A continuum theory of elastic dielectrics including polarization gradient is obtained as the long-wave approximation of a theory of lattice dynamics for the shell model of cubic ionic crystals. The additional energy associated with the formation and relaxation of a free surface is obtained by considering the unbalanced charges and dipole moments on the surface. The material coefficients of the continuum theory are related to the lattice properties, and their numerical values are calculated for NaI, NaCl, KI, and KCl. The surface energy density of a free half-space predicted by the continuum theory is compared with experimental results as well as other theoretical results based on discrete models.

Citations

• Dynamical Theory of Crystal Lattices

Related

• Macroscopic polarization from nonlinear gradient couplings
• Lattice equations and dielectric function for optical lattice vibrations in monolayer transition metal dichalcogenides
• Continuum Dislocation Dynamics as a Phase Field Theory with Conserved Order Parameters
• Dynamical Theory of Crystal Lattices
• Translational covariance of flexoelectricity at ferroelectric domain walls