Field-induced Phase Transition and Metastable Ferroelectric Phase in Antiferroelectric Creamics of (Pb,La)(Zr,Sn,Ti)O3

External field-induced phase transition in lanthanum-doped lead zirconate titanate stannate antiferroelectric ceramics near morphotropic phase boundary were studied as a function of electric field, temperature and hydrostatic pressure. Upon application of an electric field to the antiferroelectric ceramics and the electric field was larger than the critical field of E_AFF-_FE, the sample undergoes a phase transform from the antiferroelectric to ferroelectric phase, associated with an abrupt change in macroscopic properties. The polarization and longitudinal strain increased rapidly from zero to 30muC/cm² and 0.3% or so, respectively. At some conditions, the induced ferroelectric phase can remain metastable state when the electric field was removed. The metastable ferroelectric phase was unstable, which recovered to antiferroelectric phase again with the increasing of temperature and hydrostatic pressure, respectively. Large charge release from remnant polarization of metastable ferroelectric phase was observed.