摘要
In the present work we reported the phase formation, microstructure, magnetocaloric effect and hydrogenation behavior of La-rich La1.7Fe11.6Si1.4alloy. In this off-stoichiometric La（Fe,Si）13alloy, the Na Zn13-type La（Fe,Si）13matrix phase shows faceted grains, with the Cr5B3-type La5Si3 used as the secondary phase distributed intergranularly. Such a peculiar morphology quickly forms upon one day annealing. In La1.7Fe11.6Si1.4alloy, we have observed a significant field dependence of magnetostructural transition temperature（～ 6.3 K/T）, resulting in a large and table-like entropy change（△S～ 18 J/kg·K in 2 T） over a broad temperature range（～ 10 K）. Upon hydrogenation, the maximum value of △S keeps almost unchanged, while the Curie temperature increases up to 350 K. These results indicate that the investigated offstoichiometric La（Fe,Si）13alloy is a promising magnetic material for magnetic refrigerators.
In the present work we reported the phase formation, microstructure, magnetocaloric effect and hydrogenation behavior of La-rich La1.7Fe11.6Si1.4alloy. In this off-stoichiometric La（Fe,Si）13alloy, the Na Zn13-type La（Fe,Si）13matrix phase shows faceted grains, with the Cr5B3-type La5Si3 used as the secondary phase distributed intergranularly. Such a peculiar morphology quickly forms upon one day annealing. In La1.7Fe11.6Si1.4alloy, we have observed a significant field dependence of magnetostructural transition temperature（～ 6.3 K/T）, resulting in a large and table-like entropy change（△S～ 18 J/kg·K in 2 T） over a broad temperature range（～ 10 K）. Upon hydrogenation, the maximum value of △S keeps almost unchanged, while the Curie temperature increases up to 350 K. These results indicate that the investigated offstoichiometric La（Fe,Si）13alloy is a promising magnetic material for magnetic refrigerators.
基金
Project supported by the National Natural Science Foundation of China(Grant No.51371184)
the Outstanding Youth Fund of Zhejiang Province,China(Grant No.LR14E010001)
