熔体快淬La_(1-x)Nd_xFe_(11.5)Si_(1.5)(x=0,0.3,0.5)化合物磁性能和磁熵变

Magnetic Properties and Magnetic Entropy Change of LaFe_(11.5)Si_(1.5) and Melt-Spun La_(1-x)Nd_xFe_(11.5)Si_(1.5) Compounds

利用熔体快淬法制备了La1-xNdxFe11.5Si1.5(x=0,0.3,0.5)快淬带。通过X射线衍射和振动样品磁强计测试了回火态(1000℃,5h)La1-xNdxFe11.5Si1.5快淬带的相组成和磁性能。结果表明:不同成分快淬带回火后均可得到稳定的NaZn13型化合物。和常规的熔炼法相比,用熔体快淬法通过短时间的回火(1000℃,5h)可以制成具有大磁熵变的NaZn13型的化合物。用Nd替代部分的La后,居里温度略有提高,同时保持有大的磁熵变|?S|;并且随着Nd含量的增加,有效制冷温区有变宽的趋势。

The structure and magnetic properties of annealed （950℃, 100 h） LaFeH.sSil.5 ingots and annealed （1000℃, 5 h） melt-spun La1-xNdxFe11.5Si1.5（x= 0, 0.3, 0.5） ribbons were investigated by means of X-ray diffraction （XRD） and vibrating sample magnetometer （VSM）. All ribbons are in the NaZn13-type structure and no 1：13 phase is observed in ingots though their annealing time is longer than that of ribbons, which suggests that the NaZn13-type compounds with large magnetic entropy change （｜ΔS｜） can be produced by melt spinning. Therefore, the production cost will be cut significantly because of short annealing time. Curie temperature （To） is slightly improved and the effective refrigeration temperature range is slightly broadened with the Nd content increasing in La1-xNdxFe11.5Si1.5（x=0, 0.3, 0.5 ） ribbons. In summary, La1-xNdxFe11.5Si1.5 ribbons with x=0.3 have the best refrigeration efficiency and they are promising to become low-cost, high efficiency magnetism refrigeration materials near room temperature.