Influence of yttrium on the magnetic properties of amorphous Fe91-xYxZr9 alloys

In this article, we investigate and discuss the influence of the substituting Fe with Y on the magnetic properties of amorphous Fe91Zr9 alloys prepared by single-roll melt spinning technique. The temperature dependence of magnetization for amorphous Fe91-xYxZr9 alloys, at low fields, shows the existence of antiferromagnetic (AFM) couplings between Fe atoms. On increasing the concentration of Y, the strength of the AFM interactions is suppressed and the Curie temperature T-C increases, which can be explained on the basis of the atomic size effect of Y. From an analysis of the approach to saturation magnetization M-S, the magnetic moment mu(Fe) per Fe atom, anisotropy field, and local random anisotropy constant K-1, have been extracted. It is found that mu(Fe) increases from 1.57 to 2.04 mu(B) and K-1 decreases with increasing Y concentration. This result suggests that the substitution Fe with Y seems to favor the increase of magnetic order by reducing the random anisotropy and thus change the magnetic structure from being an asperomagnetic to a ferromagnetic one. (C) 1997 American Institute of Physics.