Research on electrostrictive effect of second-order phase transition ferroelectrics

ABSTRACT Reversible electrostrictive effect in ferroelectrics of double-well free energy is modeled using the Devonshire theory. The idea is developed that in tetrogonal phase 90° turnings of dipoles from four poling axises, isoenergetic minima, perpendicular to electrical field to the direction of electrical field cause electrostriction. Numerical simulation results exhibit that the exchanging coupling coefficient between dipoles results in a butterfly shaped electrostriction loop. Influences of temperature and the two parameters of materials on shape of electrostriction loop are discussed, and an empirical experimental law, about magnitude of electrostriction with the Curie constant, is confirmed.