Longitudinal and Transverse Electrocaloric Effects in Glycinium Phosphite Ferroelectric

Abstract

A modified proton ordering model of glycinium phosphite ferroelectric, which involves the piezoelectric coupling of the proton and lattice subsystems, is used for the investigation of the electrocaloric effect. The model also accounts for the dependence of the effective dipole moment on a hydrogen bond on an order parameter, as well as a splitting of parameters of the interaction between pseudospins in the presence of shear stresses. In the two-particle cluster approximation, the influence of longitudinal and transverse electric fields on components of the polarization vector and the dielectric permittivity tensor, as well as on thermal characteristics of the crystal, is calculated. Longitudinal and transverse electrocaloric effects are studied. The calculated electrocaloric temperature change is quite small, about 1K; however, it can change its sign under the influence of a transverse field.