中文摘要：

通过吸氢、放氢调节La0.8Ce0.2Fe11.44Si1.56Hy合金的居里温度,利用X射线衍射物相分析（XRD）和振动样品磁强计（VSM）测量了合金的相结构和磁性曲线。结果表明：La0.8Ce0.2Fe11.44Si1.56合金吸氢后磁性能稳定,同时由于巡游电子变磁（IEM）转变减弱导致磁滞显著减小,但可以保持较大等温磁熵变。在0~1.5 T外加磁场下La0.8Ce0.2Fe11.44Si1.56Hy合金的最大等温磁熵变可以达到11.3 J·（kg·K）-1,大约是金属Gd的4倍。一定温度下、不同保温时间的放氢工艺可对氢含量进行微调,使La0.8Ce0.2Fe11.44Si1.56Hy合金的居里温度在283~316 K之间可调,而且不会影响合金等温磁熵变的大小,因此通过吸、放氢可以有效的在室温附近调节La0.8Ce0.2Fe11.44Si1.56Hy的居里温度。

英文摘要：

Curie temperatures of Lao.s Ceo.2 Fe11.44 Si1.56 Hy were adjusted by hydrogen absorption and desorption, and the phase struc- tures and magnetic curves of the alloys were detected by X-ray diffraction （XRD） and vibrating sample magnetometer （VSM） analysis apparatus, respectively, The results showed that magnetic properties of the Lao.s Ceo.2Fe11.44Si1.56 alloys remained stable after hydrogen absorption, and magnetic hysteresis reduced remarkably because of the weakness of the itinerant-electron metamagnetic transition, while the large magnetic entropy change was retained. The maximum magnetic entropy change of La0.8Ce0.2Fe11.44Si1.56Hy alloy was 11.3 J.（kg·K） -1 in a changing magnetic field of 0 ~ 1.5 T, which was about four times that of Gd. Under the specific temperature and different holding time, hydrogen desorption could finely adjust the hydrogen content and hardly influenced the magnetic entropy changes of the alloys. The Curie temperatures of Lao.sCe0.2Fe11.44Si1.56Hr could be tuned from 283 to 316 K, so the Curie temper- atures of La0. 8Ce0.2Fe11.44 Si1.56 Hy could be efficiently adjusted by hydrogen absorption and desorption in the room temperature range.