Electrocaloric effect of lead-free inorganic (1-x) [Bi0.5(Na0.84Ka0.16)0.5]TiO3+xBaTiO3+0.3wt%Nb2O5 ceramics

In this work, in order to develop the ceramics with an excellent electrocaloric effect, (1-x) [Bi0.5(Na0.84Ka0.16)0.5]TiO3+xBaTiO3+0.3wt%Nb2O5 [(1-x)BNKT-xBT] ceramics (x = 0, 0.04) were fabricated by conventional solid state reaction method. To investigate the electrocaloric effect of the ceramics, P-E hysteresis loops were measured in various temperature ranges from room temperature to 200°C. The adiabatic temperature change ΔT of these ceramics was measured using indirect method, which was calculated using the Maxwell's relations. The optimal value of adiabatic temperature change ΔT was obtained as 0.31°C at 165°C under applied electric fields 45 kV cm in x = 0 ceramics.