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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。
The Curie temperature of La0.8Ce0.2Fe11.44Si1.56Hy alloy was adjusted by hydrogen absorption and desorption. The phase structure and magnetic curve of the alloy were measured by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) . The results show that the magnetic properties of La0.8Ce0.2Fe11.44Si1.56 alloy are stable after hydrogen absorption, meanwhile the hysteresis of the La0.8Ce0.2Fe11.44Si1.56 alloy is stable due to the weakening transition of IEM. However, the larger isothermal magnetic entropy change can be maintained. The maximum isothermal magnetic entropy change of La0.8Ce0.2Fe11.44Si1.56Hy alloy can reach 11.3 J · (kg · K) -1 at 0 ~ 1.5 T applied magnetic field, which is about 4 times of metal Gd. At a certain temperature, the hydrogen release process with different holding time can finely adjust the hydrogen content so that the Curie temperature of La0.8Ce0.2Fe11.44Si1.56Hy alloy can be adjusted between 283 and 316 K without affecting the isothermal magnetic alloy Entropy change the size, so by absorbing, releasing hydrogen can effectively adjust the Curie temperature of La0.8Ce0.2Fe11.44Si1.56Hy near room temperature.