稀土纳米磁致冷复合材料

PREPARATION OF RARE-EARTH NANOCOMPOSITE SOLIDS FOR MAGNETIC REFRIGERATION

采用急冷快谇，高能球磨及粉末包套包覆轧制方法制备出Ｇｄ－Ｙ，Ｇｄ－Ｚｎ和Ｇｄ－Ｔｂ的纳米固体复合磁致冷材料。实验测试结果表明：与大块状材料相比，纳米固体的居里温度明显降低，比热显著增加；Ｇｄ－Ｔｂ和Ｇｄ－Ｚｎ合金的磁热熵效应有所降低，但Ｇｄ－Ｙ系的磁热熵效应则显著增加。对制备工艺条件及若干影响磁热熵效应的因素进行了较详细的分析。

The nanocomposite solids of rare-earth alloys Gd-Y, Gd-Zn and Gd-Tb for magnetic refrigerant have been prepared by means of rapid quenching and ball-milling as well as powder coating-rolling. It turns out that both Curie temperature and specific heat of the prepared nanocomposite solids, compared with the bulk materials, show obviously decrease and increase respectively. The magnetocaloric effect(MCE) of Gd-Y alloy demonstrates an unique raising rather than reducing of both Gd-Tb and Gd-Zn. A discussion concerning the influence of preparing parameters on magnetocaloric effect is given in detail.