摘要
The article presents the results of research the pre-transitional features of the behavior of solid solutions based on lead zirconate-titanate.The presence of a“special”critical temperature T_(d)on the temperature dependences of the permittivityε(T)and the remanent polarization P_(r)(T),preceding the temperature of the paraelectric phase transition at the Curie temperature T_(C),is noted.In the temperature range T<T_(d),the P_(r)(T)dependence obeys a power law.In the temperature range T_(d)<T<T_(C),this law is not fulfilled.The results of X-ray experiments make it possible to associate this behavior with reversible disordering at T<T_(d)of an ordered domain structure formed during the polarization of piezoelectric ceramics and with its irreversible disordering in the temperature range T_(d)<T<T_(C).This is due to the appearance of internal mechanical stresses in a polycrystalline ferroelectric due to irreversible depolarization of the samples at temperatures T_(d)<T<T_(C).
