Synthesis and magnetic properties of off stoichiometric Laves phase Fe_2Nb amorphous alloy

摘要

The formation process and magnetic properties of the distorted Laves phase compound (Fe_2Nb) of the nominal composition Fe_(60)Nb_(40) in its amorphous phase prepared by mechanical alloying have been investigated. The effect of milling time on the formation of amorphous phase has been studied using the X-ray diffraction technique. Further characterizations were carried out by particle size measurement, energy dispersive X-ray microanalysis (EDAX), dc magnetisation and ferromagnetic resonance (FMR) studies. Magnetisation measurement shows that the deviation from the stoichiometric composition in the Nb rich side enhances the compositional short range order and favours the moment formation responsible for weak ferromagnetic behaviour whereas ferromagnetic resonance spectra show some sort of disorder/strain introduced during the mechanical alloying process. The method of preparation also affects the magnetic behaviour of nominal composition