摘要
(Ba_(1-x)Sr_(x))(MnyTi1-y)O_(3)(BSMT)ceramics with x=35,40 mol%and y=0,0.1,0.2,0.3,0.4,0.5 mol%were prepared using a conventional solid-state reaction approach.The dielectric and ferroelectric properties were characterized using impedance analysis and polarization-electric field(P-E)hysteresis loop measurements,respectively.The adiabatic temperature drop was directly measured using a thermocouple when the applied electric field was removed.The results indicate that high permittivity and low dielectric losses were obtained by doping 0.1-0.4 mol%of manganese ions in(BaSr)TiO_(3)(BST)specimens.A maximum electrocaloric effect(ECE)of 2.75 K in temperature change with electrocaloric strength of 0.55 K·(MV/m)^(-1)was directly obtained at~21℃and 50 kV/cm in Ba_(0.6)Sr_(0.4)Mn_(0.001)Ti_(0.999)O_(3) sample,offering a promising ECE material for practical refrigeration devices working at room temperature.
基金
This work was supported by the National Natural Science Foundation of China(Grant Nos.51372042 and 51872053)
the Guangdong Provincial Natural Science Foundation(Grant No.2015A030308004)
the NSFC–Guangdong Joint Fund(Grant No.U1501246)
the Dongguan City Frontier Research Project(Grant No.2019622101006)
the Advanced Energy Science and Technology Guangdong Provincial Laboratory Foshan Branch-Foshan Xianhu Laboratory Open Fund-Key Project(Grant No.XHT2020-011).
