Magnetic properties of amorphous Gd 4Fe 3 and Y 4Fe 3 alloys

Abstract

Amorphous alloys with non-S state rare earth ions (Gd 4Fe 3 and Y 4Fe 3) are prepared as ribbons. The amorphism is proved by X-ray diffraction and differential scanning calorimetry. The crystallization of the alloys was studied using a variable heating rate and the results were analysed by Kissinger's method. The phases formed during the crystallization process were identified by means of X-ray diffraction and thermomagnetic measurements. The magnetic properties were investigated from 4.2 to 400 K in steady fields of up to 140 kOe. A spin-glass-like behaviour was observed for the amorphous Y 4Fe 3 alloy and this was due to the presence of both positive and negative exchange interactions. The observed reduction in the iron magnetic moment was discussed in terms of the environmental model of Jaccarino and Walker. The magnetic properties of the alloys investigated were compared with those of similar rare earth alloys containing cobalt instead of iron.