The electrocaloric effect in 0.94(Bi_0.5Na_0.5)TiO₃+0.06KNbO3+0.9 wt% G.F.ferroelectricceramics was observed in terms of the temperature change (ΔT) of the fabricated ceramics, Curie temperature Tc, and applied electric field. The specimens were fabricated by a conventional solid-state reaction. T_c appeared near 165∼170℃. The P-E hysteresis showed a tendency to slim down with a temperature increase and finally was slimmest near 150℃. With the increase of temperature, the polarization revealed a gradual decrease, and a sharp decline near T_c. When an electric field of 45 kV/cm was applied, the largest polarization was shown. The maximum value of the temperature change (ΔT=0.31℃) was obtained at 165℃ under an applied electric field of 45 kV/cm.

In this study, in order to develop the composition ceramics with the excellent electrocaloric properties, 8/65/35 PLZT ceramics were fabricated by the conventional solid-state method with the addition of Bi2O3, CuO, Li2CO3 and the variation of sintering temperature from 930℃ to 990℃. The XRD pattern of all specimens indicated general perovskite structure and the rhombohedral phase were observed. Curie temperature (Tc) of all specimens was observed in the vicinity of about 190℃. Density, coercive field and remnant polarization of the specimen sintered at 950℃ was 7.55 g/cm3, 8.895 kV/cm, 11.22 μC/㎠, respectively. EC effect of PLZT ceramics was measured by indirect method and the temperature change ΔT due to the electrocaloric effect was calculated by Maxwell’s relations. ΔT of ceramic sintered at 950℃ was 0.21℃ under application of 40 kV/cm at 190℃.