Magnetic properties and exchange interactions in T sub 100-x Er sub x amorphous alloys (T=Fe, Co)

Amorphous T sub 100-x Er sub x (with T=Fe,Co and 6 < x < 30) thin films were prepared by RF sputtering and their magnetic properties have been studied. A mean field model has been used to explain a temperature dependence of the magnetization. This analysis yields the spin values of T and the effective exchange interaction between T-T and T-Er atoms. High-field magnetization studies performed at 4.2K in magnetic fields up to 5.5 tesla on amorphous T sub 100-x Er sub x alloys have revealed for samples with stoichiometry close to that of compensated ferrimagnet, a magnetic behavior that is characteristic of a non collinear magnetic structure of Er and T sublattices.