Preparation and properties of Mg-Fe nanocomposite

Abstract

The Mg-Fe nanocomposite synthesized by spark erosion of pure Mg and Fe electrodes was investigated by X-ray diffraction. Mössbauer spectroscopy and magnetic measurements. From the X-ray diffraction measurements Mg, MgO, and α-Fe were recognized. According to the Mössbauer spectra analysis, iron atoms were identified in α-Fe, Fe in Mg/MgO (mf), and Fe1-xO phases. The mf phase consists of an amorphous part (paramagnetic down to 20 K), weak ferromagnetic Fe in Mg, and fcc iron clusters (particles) which are antiferromagnetic below TN ≈ 60 K. Measurements of the thermomagnetic curves show spin-glass-like behaviour of the as-prepared powder. Transformation of the mf phase in α-Fe and Fe1-xO phases was observed after annealing at temperatures above 200 °C.