A structural, magnetic and mössbauer investigation on melt-spun Nd0.33(Fe0.75Al0.25)0.67 ribbons

Abstract

A tetragonal phase with a = 9.778 Å and c = 11.516 Å is formed in the Nd0.33(Fe0.75Al0.25)0.67 alloy after melt spinning and short period annealing at 873 K. The tetragonal phase is probably metastable and transforms slowly into the stable δ-Nd3Fe7-xAlx phase during heat treatment at 873 K. This phase is antiferromagnetic with a Néel temperature of 260 ± 5 K. Metamagnetism is observed at a temperature of 140 K or below. The magnetic properties have been characterized using a vibrating sample magnetometer and Mössbauer spectroscopy. Magneto-resistivity of up to 7.2% is accompanied by metamagnetism. At room temperature, 1% of the magneto-resistivity is measured in the paramagnetic state.