Magnetic properties of amorphous Fe100-xErx alloys

We have prepared Fe100-alphaErx thin films by RF sputtering and studied the ir magnetic properties. The mean field theory has been used to explain the temperature dependence of the magnetization which firstly decreases with in creasingly and reaches a compensation for x = 20.5% at 4.2 K. This analysis yields the effective exchange interaction between Fe-Fe and Fe-Er atom pai rs. From an analysis of the approach to saturation magnetization, the local random anisotropy constant K-L has been extracted. The ferromagnetic corre lation length R-f decreases with increasing Er content. (C) 1999 Elsevier S cience B.V. All rights reserved.