Structure and magnetic properties of Sm(Fe,Si)9C/α-Fe nanocomposite magnets

SmFe8.75 Si0.25 C/α-Fe nanocomposites have been successfully synthesized using high energy milling, followed by annealing at 750 °C. The crystal structure of these compounds was characterized by the Rietveld method using powder X-ray diffraction data. By increasing the concentration of Sm, we observed a decrease in the amount of α-Fe phase. The morphology of the samples was determined by scanning and transmission electron microscopy. The average grain size is about 20 nm. The magnetic properties were investigated at room temperature and at 10 K. A ferromagnetic behavior was observed in all samples at both temperatures. An increase of the soft magnetic phase α-Fe induced an increase in the magnetization and a decrease in coercivity.