Field induced effect of relaxor ferroelectrics at high electric field

Abstract

Relaxor ferroelectrics have been widely used in dielectric, pyroelectric, electric field modulation microwave devices and electrostriction device. These applications refer to effect of electric field, increase in strength of polarization from ferroelectric phase stretching to paraelectric phase successively, to give rise to an effect similar to field induced effect. A result of the peak temperature of dielectric permittivity changing with the electric field 2/3 power was obtained by using approximation method, which is coincident with the experimental result of dielectric peak. The numerical simulation results found that there exist a thermal dynamics related polarization-temperature coefficient. Increasing the coefficient will decrease shift effect of dielectric peak, or will decrease effect of field induced phase transition, but, will increase pyroelectric effect. On the contrary, the stronger shift effect of dielectric peak will increase dielectric tunability and its temperature stability for electric field modulated microwave devices. The above theoretic results have certain reference implications for dielectric tunability of microwave device and pyroelectric property by doping modification method.