Magnetic Properties of Amorphous Si-M(M=Fe or Co)Alloy Powder Produced by Mechanical Alloying
Crystalline powders of Si and M(Fe or Co) in the composition ratio varying from Si:M=1:2 to 2:1 were mechanically alloyed by laboratory ball milling in an inert atmosphere. The amorphization reaction between Si and M proceeded according to a second-order reaction. The reaction rate for a Si–Co system was faster than that for a Si–Fe system. Moreover, the thermal behavior of the amorphous SixM1-x powders synthesized by mechanical alloying has been studied by DTA, X-ray diffraction and measurement of saturation magnetization. The coercive force of milled Si–M powders was maximum at 60–80 mol% of Co-content for Si–Co systems and 70–90mol% Fe-content for Si–Fe systems, respectively. This value was larger than that of the corresponding mixture of crystalline powders. On the other hand, it was found that the coercive force of amorphous samples decreased abruptly at a temperature corresponding to the transformation from an amorphous state into a crystalline state began to occur.
- Materials transactions, JIM
Materials transactions, JIM 37(5), 1099-1102, 1996-05