Dielectric response of ceramic 16BiScO$_{3}$–42PbMg$_{1/3}$Nb$_{2/3}$O$_{3}$–42PbTiO$_{3}$ solid solutions in an electrical field

Some results of studying the dielectric and electromechanical properties of ceramic 16BiScO$_{3}$–42PbMg$_{1/3}$Nb$_{2/3}$O$_{3}$–42PbTiO$_{3}$ relaxor ferroelectric samples in electrical fields (0 $<E<$ 20 kV/cm) are presented. An appreciable decrease in the dielectric permittivity with time, and the disappearance of hysteresis in the dependence of the longitudinal strain on the electrical field intensity were revealed in the fields exceeding the coercive field ($E>$ 10 kV/cm) and explained by the induced ferroelectric phase transition. The field-induced phase (presumably, tetragonal) was shown to be unstable and partially ordered. A nonmonotonical character demonstrated by the dielectric permittivity–time dependences of the studied ceramics unlike the other relaxor ferroelectrics was explained by the coexistence of glassy and ferroelectric phases.