The dynamics of polarization reversal in de field was studied in various te
mperatures in the course of heating process from room temperature to the Cu
rie point T-c. The time dependence of domain pattern appearing during the p
olarization reversal was analysed using the Avrami theory. Observation of d
omain switching in the vicinity of T-c after quenching the crystal from par
aelectric phase was also carried out.