The Magnetic Moment of Fe Atom in 1∶13 Phase for Different LaFe11.6×xSi1.4 Alloys

Without considering the defects, a systematic investigation is conducted, by means of experiment, to determine the average magnetic moment of Fe atom in pure Fe and different LaFe11.6×xSi1.4 alloys.The results show that the saturation magnetic moments of pure Fe are 213 A·m2/kg at 180, 185, 190, and 195 K;the average saturation magnetic moment of every single pure Fe atom is 2.12μB.The theoretic value of the saturation magnetic moment of LaFe11.6Si1.4 alloy should be 166 A·m2/kg emu/g, and the experimental value of the isothermal magnetic entropy change is 41.5 J/kg·K.The maximum magnetization of LaFe11.6Si1.4 alloy melted by non-consumable arc furnace and annealed by short-time high-temperature heating is only 112 A·m2/kg, and the average magnetic moment of the Fe atom of 1:13 phase in the alloy is 1.43μB;In one LaFe11.6Si1.4 crystal cell, there are 7.8 effective Fe atoms which have made contribution to the magnetic moment of the alloy.The magnetization of LaFe11.6Si1.4 kg alloy produced by medium-frequency induction furnace under the same temperature is only 125 A·m2/kg, whose average magnetic moment of Fe atom is 1.59μB, and in each LaFe11.6Si1.4 crystal cell there are 8.7 effective Fe atoms that have contribution to the alloy magnetic moment.However, excess Fe in the LaFe11.6×xSi1.4 samples has a significant effect on enhancing the magnetization.The technique saturation magnetization of 1∶13 in LaFe11.6×1.05Si1.4 and LaFe11.6×1.1Si1.4 alloys are 146 A·m2/kg and 155 A·m2/kg, respectively.The effective magnetic moment of Fe atom reaches about 1.86μB which is significantly higher than the average effective magnetic moment of Fe atom of 1:13 phase in LaFe11.6Si1.4.