DENSIFICATION AND FREQUENCY DIELECTRIC RESPONSE (10(2) TO 10(9) HZ) OF FERROELECTRIC K(TA0.5NB0.5)O-3 CERAMICS

The frequency dielectric response in K(Ta0.5Nb0.5)O-3 ceramics (KTN) i s investigated over the temperature range 280 to 450 K and over a wide range of frequency (10(2) to 10(9) Hz). The KTN ceramics are sintered using Li2CO3 as an addition, allowing liquid phase sintering. Dielect ric measurements are performed on two samples:a fast fired sample and a conventionally fired one. The ferroelectric-paraelectric transition occurs at T-C approximate to 380 K; it is a first-order transition. Tw o dielectric dispersions are observed: a polydispersive low Frequency one (10(2) to 10(5) Hz) and a high frequency relaxation (10(8) to 10(9 ) Hz). The latter is explained on the basis of correlation chains or c orrelation volumes in a double potential well model.