【摘要】 利用非晶态分子合金作前驱体,在相对低的热分解温度800℃、10h成功合成了钙钛矿结构(La0.52Gd0.15)Sr0.33MnO3多晶颗粒。TEM观察表明,颗粒的尺寸范围为100~150nm。研究了多晶颗粒(La0.52Gd0.15)Sr0.33MnO3的居里温度和磁熵变化(MCE)。在多晶颗粒(La0.52Gd0.15)Sr0.33MnO3中,居里温度(343K)附近观察到较大的磁熵变和较宽的峰值温度范围,较大的磁熵变来源于磁场条件下的铁磁转变贡献。这些结果表明,该材料是室温附近磁制冷合适的工作物质。更多还原

【Abstract】 Polycrystalline particles(La_0.52Gd_0.15)Sr_0.33MnO₃ oxide with perovskite structure was successfully synthesized by the decomposition of the amorphous precursor at fairly low temperature 800℃ for 10h.TEM showed the resulted particle size is about 100～150nm.The Curie temperature TC and magnetic entropy change（MCE） in the(La_0.52Gd_0.15)Sr_0.33MnO₃ polycrystalline particles have been analyzed.A relatively large magnetic entropy change with a broad peak around Curie temperature（343K） is observed in(La_0.52Gd_0.15)Sr_0.33MnO₃ polycrystalline particles.The large entropy change could be attributed to the ferromagnetic transition at an applied field.These results suggested that this material is a suitable candidate as working substance in magnetic refrigeration near room temperature.更多还原