In this study, in order to develop relaxor ferroelectric ceramics for refrigeration device application with large electrocaloric effect and low sintering temperature, PLZT(8/65/35) ceramics was fabricated using conventional solid-state method with the variation of sintering temperature (1,050℃, 1,100℃, 1,200℃). The XRD pattern of all specimens indicated general perovskite structure with secondary phase. From the results of temperature dependence of dielectric constant, the TC (ferroelectric-paraelectric phase transition temperature) was shifted toward high temperature with increasing sintering temperature. When the specimen was sintered at 1,100℃, the optimal value of .T ∼0.349℃ in ambient temperature of 215℃ was appeared. It is considered that PLZT(8/65/35) ceramics possess the possibility of refrigeration device application.

In this study, in order to develop relaxor ferroelectric ceramics for refrigeration device application with large electrocaloric effect, PLZT(8/65/35) composition was fabricated using conventional solid-state method. The Curi temperature of this composition PLZT ceramics was 230℃, and the P-E hysteresis loops of the PLZT ceramics as a fuction of temperature became slim by degrees with higher temperatures. The maximum value of .T of 0.243°C in ambient temperature of 215°C with 30 kV/cm was appeared. It is considered that PLZT ceramics possess the possibility of refrigeration device application.

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℃.

In this study, in order to develop the composition ceramics with the excellent electrocaloric properties, (Pb0.88La0. 08)(Zr0.65Ti0.35)O3 ceramics were fabricated by the conventional solid-state method. Electrocaloric effects of (Pb0.88La0.08)(Zr 0.65Ti0.35)O3 ferroelectric ceramics were investigated and discussed using the characteristics of P-E hysteresis loops at wide temperature range from room temperature to 220 . The temperature change ΔT due to the electrocaloric effec t was calculated by Maxwell’s relations, and reached the maximum of 0.19 at 190 under applied electric field of 30 kV/cm.