【摘要】 采用固相反应烧结法制备了(La0.7-xGdx)Pb0.3MnO3(X=0,0.15,0.2,0.25)多晶样品,对样品的磁性随外场与温度的变化进行测量,确定样品的居里温度并计算了样品的磁熵变。对样品的居里温度随A位离子平均半径r的变化规律进行了定性分析。更多还原

【Abstract】 A series of polycrystal samples of (La 0.7-xGd x)Pb 0.3MnO 3(X=0, 0.15, 0.2, 0.25) was prepared by solid state reaction of precursor oxides. The dependence of magnetization on the applied magnetic field and temperature was measured. It was found that the curie temperature T c of samples decrease with the decreasing of the average ionic radius of the A site r. The entropy change of (La 0.7-xGd x)Pb 0.3MnO 3 for x=0.15 is about 1.0 J·kg-1·K-1 under a magnetic field 6T. The finding is important for developing new material for magnetic refrigeration in high temperature or near room temperature.更多还原