Mössbauer and magnetic studies on nanocrystalline FeNi particles prepared by thermal reduction

The development of technology in recent years requires cheap, high-performance magnets. One promising candidate for rare-earth-free hard magnetic materials seems to be FeNi-based alloys, especially L1₀-FeNi phases. This study explores the thermal decomposition of oxalate precursors synthesized by coprecipitation and subjected to controlled thermal decomposition in a hydrogen atmosphere to produce FeNi alloy particles. Physical characterization was conducted using Mössbauer spectrometry, X-ray diffraction, magnetization measurements, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. X-ray diffraction and Mössbauer spectroscopy indicated a mixture of bcc α-Fe(Ni) and fcc iron-nickel phases. Magnetic measurements confirmed the formation of magnetically suitable FeNi phases.