Effect of Low Doped Calcium on the Magnetic Properties of La_0.7Ba_0.297Ca_0.003MnO₃ for Magnetocaloric Application

Effect of low doped calcium concentration to the magnetic properties of La_0.7Ba_0.3MnO₃ material has been reported in this paper. This compound was chosen because it has high potential to be applied in electronic devices. The most intensive research in the last decade is about magnetocaloric effect (MCE). Magnetic refrigeration will replace Freon R12 that is used in conventional refrigeration with magnetic material which has MCE properties. It is due to conventional refrigeration produce chlorofluorocarbons (CFC) and hydrochlorofluorocarbons (HCFCs) gases which causes ozone depletion. The magnetic measurement was performed by using Vibrating Sample Magnetometer in the range of temperature between 300-400 K under external magnetic field until 20 kOe. By using derivative of magnetization as a function of temperature of the material's result, Curie temperature (T_c) of the material is 332.7 K. By using equation (5) for calculating magnetic field dependence of magnetization at various temperature result, magnetic entropy change value (ΔS_M) of the material can be obtained. The ΔS_M of the material is -2.928 Jkg^-1K^-1. The material has highest magnetic entropy change value around its T_c. It is due to there is strong lattice spin coupling around its T_c and would be weak at below and above its T_c. (paper)