Parameters of phase transitions in disordered ferroelectrics with random electric and elastic fields

Abstract

The distribution function of random electric fields, which allows for the correlation between the sources of electric and elastic fields has been calculated for the first time from the main characteristics of the functions E_m and I(E = E_m ), the most probable electric field and its maximal intensity, respectively. This made it possible to calculate several parameters of the ferroelectric phase induced by electric dipoles in disordered ferroelectrics. It was shown that the transition temperature T_cmf in the mean field approximation, the piezoelectric tensor components which appear at T < T_cmf , as well as the critical concentration of electric dipoles, decrease with increasing concentration of the elastic dipoles.