Kinetic study of PZN single crystal polarization under a static electric field

A kinetic effect is evidenced in lead zinc niobate (PZN). We measured the time dependencies of the polarisation P(t) of a single crystal. At a given temperature and electric field, P(t) is described by the expression P(t) = P-infinity(T) f(t/tau(E,T)) where tau(E,T) is the incubation time above which the sample is completely polarised. The tau(E,T) was fitted using the exponential law exp[(W+k delta(T)/E)/kT] where the activation energy W is equal to 0.91+/-0.36 eV and delta(T) is equal to 2.2x10(8) K V/m in the 30-360 K temperature range. Taking into account this kinetic effect the electric-field-temperature diagram and the existence of an electric field threshold were discussed.