Direct Measurement of Enhanced Electrocaloric Effect in Mn 2+ Doped Lead-Free Ba(ZrTi)O 3 Ceramics

The manganese doped barium zirconate titanate ceramics (Ba(ZrxMnyTi1-x-y)O3-BZMT) ceramics with x= 0.15, 0.20 and y=0, 0.0025, 0.0050, 0.0075, 0.0100, 0.0250, 0.0500 were prepared using an oxide reaction approach. The adiabatic temperature change was measured directly. Results revealed that by adjusting the nonequivalent Mn2+ ionic concentration within 0.25% to 0.75%, desired dielectric performances with high permittivities and lower losses were obtained. The polarization was increased with the doping content of Mn2+ ions. The largest electrocaloric temperature change obtained is 2.35 K for Ba(Zr0.15Mn0.0025Ti0.8475)O3 ceramics at 62°C, and a broad temperature range of ~ 40°C was accompanied.