Preparation of iron–platinum nanoparticles in water/triton/cyclohexane microemulsions

Iron–platinum (FePt) nanoparticles at two different molar ratios of Fe2+ to Pt4+ of 1:1 and 3:1 have been prepared by coreduction of H2PtCl6 and FeCl2 with hydrazine in water/triton X-100/cyclohexane microemulsions. The as-synthesized FePt nanoparticles were characterized by XRD, EDX and TEM. The FePt nanoparticles showed disordered fcc structure having 4.7 nm crystallite size—larger than the superparamagnetic limit. Higher content of iron resulted in larger FePt nanoparticles. Magnetic properties of the as-synthesized FePt nanoparticles were investigated using AGM. The hysteresis loops revealed that FePt nanoparticles exhibited soft magnetic behavior with high saturation magnetization. However, the FePt nanoparticles with the molar ratio of 3:1 possessed lower values of the coercive force (Hc) and magnetization.