LAW OF APPROACH TO MAGNETIC SATURATION IN INHOMOGENEOUS FERRI-MAGNET AND ANTIFERROMAGNETS AND IN AMORPHOUS IRON-RICH FE-ZR ALLOYS

The magnetization curve of a two-phase two-sublattice model is calculated analytically. In one phase a ferromagnetic coupling is assumed which contributes to the total magnetization whereas in the other phase a ferromagnetic interaction takes place. Within the framework of a molecular field theory the magnetization curve of this ferromagnetic phase is calculated assuming a certain distribution of the molecular field interactions. The law of approach to magnetic saturation yields for the leading term a H-1-dependence in contrast to fluctuations of the local magnetic anisotropy which in general yield a H-1/2-law. The calculations of the two-phase two-sublattice model agree well with measurements of the high-field magnetization curve of amorphous Fe1-xZrx-alloys with 0.076 less-than-or-equal-to x less-than-or-equal-to 0.11 showing that with decreasing Zr-content an increase of the ferromagnetic phase exists.