INTRINSIC MAGNETIZATION OF FE-NI-MN ALLOYS

The saturation magnetization of fcc FeSingle Bond signNiSingle Bond signMn alloys was measured by a force technique at temperatures from 77°K to the Curie temperature. Additions of Mn were found to increase the atomic moment only for alloys with Ni-to-Fe ratio of 4/1. In this series, a maximum in atomic moment was observed for Mn concentration between 2.5 and 5.0 at.%. For Ni-to-Fe ratios of 3/2 and 2/3, Mn additions decreased the atomic moment, such decrease being more severe as iron content is increased. The effect of Mn on the Curie temperature is similar, except that no increase was observed in alloys with Ni-to-Fe ratio of 4/1. Results are satisfactorily explained using a Heitler-London model for the 3d electrons in which the atomic moment associated with each atom is determined by the principle of maximum spin and the sign of the interaction between neighboring pairs. © 1969 The American Institute of Physics.