Linear and nonlinear dielectric constant as function of bias electric field in relaxor materials

The quasistatic linear and nonlinear dielectric constants es in 9/65/35 PLZ T ceramics and PMN crystal were investigated by means of the charge accumul ation technique and by monitoring the first, epsilon (1), and,the third, ep silon (3), harmonic response. The zero field cooled and field cooled static susceptibilities show a crossover from a nonergodic relaxor to inhomogeneo us ferroelectric behaviour. At electric fields above the critical value con tribution from the saturated spontaneous polarization was observed. The tem perature dependence of the total third order nonlinear response was determi ned in 9/65/35 PLZT ceramics. (C) 2001 Elsevier Science Ltd. All rights res erved.