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.
Polycrystalline particles (La0.52 Gd0.15 )Sr0.33 MnO3 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 (La0.52 Gd0.15 )Sr0. 33 MnO3 polycrystalline particles have been analyzed. A relatively large magnetic entropy change with a broad peak around Curie temperature (343K)is observed in (La0.52 Gd0.15 )Sr0.33 MnO3 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.
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