Effect of charged dislocations on dielectric, piezoelectric and elastic properties

Abstract

A generalized treatment of the effect of charged dislocations on dielectric, piezoelectric and elastic properties is developed by considering the displacement of a charged dislocation segment, bounded by immobile pinning points, under separate or combined application of electric and elastic fields. Expressions for contributions to the dielectric constants Δχ ij, piezoelectric constants Δd imn and elastic compliances ΔS klmn are then derived, and their significance is discussed. Combined application of static electric and elastic fields or alternating electric and elastic fields yields Δd imn directly, whereas application of either an alternating electric or elastic field and a static field of the other kind yields either Δχ ij or ΔS klmn diminished by a factor containing the static field to the second power. Second-order piezoelectric phenomena, represented by the difference between mechanically clamped and free dielectric constants or electrically clamped and free elastic constants, provide additional ways to determine the magnitude of Δd imn.