Calculation of Crystal Structures, Dielectric Constants and Piezoelectric Properties of Wurtzite-Type Crystals Using Ab-Initio Periodic Hartree-Fock Method

Abstract

Methods to calculate the dielectric constant, piezoelectric constant, and electromechanical coupling factor are proposed based on ab-initio Hartree-Fock periodic calculation. Crystal structures, dielectric constants and piezoelectric properties are calculated for the wurtzite-type compounds AlN and ZnO. Calculated structures well reproduce the experimental ones within an error of 1%. The present calculations tend to overestimate both effective charges and transverse optical phonon frequencies. The dielectric constants at constant stress and strain, piezoelectric constants and electromechanical coupling factors are also calculated, and the nature of piezoelectric properties is discussed.