采用溶胶-凝胶法制备了La0.5Sr0.5Mn1-xCoxO3(x＝0.1～0.5)的系列样品,通过XRD、SEM和VSM对样品进行了表征.结果表明:随着Co3+离子掺杂量的增加,样品的结构由正交晶系向单斜晶系转变,这种现象的产生是由于Co3+离子半径(r＝0.754nm)与Mn3+离子半径(r＝0.68nm)不匹配造成的.样品形貌为均匀的球形,平均直径50nm左右.样品的居里温度和居里温度附近的磁熵变随Co3+掺杂量的增加先下降后升高,这是由于参加双交换作用的离子数目减少和结构畸变导致的.
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