Structural and magnetic properties of the ordered FePt3, FePt and Fe3Pt nanoparticles.

Abstract: The Fe x Pt100−x nanoparticles (NPs) with different nominal atomic rations (30≤x≤80) were synthesized at 700°C by the sol–gel method. The structure, morphology and magnetic properties of the samples were investigated. When the Fe content in the Fe–Pt alloy NPs was 30at%, FePt3 NPs were successfully synthesized. With the increase in Fe content up to 50at%, it was found that the superlattice reflections (001) and (110) appeared, which indicated the formation of the L10-FePt phase. Meanwhile, the FePt3 fraction was reduced. When the Fe content increased to 60at%, single-phase L10-FePt NPs were synthesized. The coercivity (Hc), saturation magnetization (Ms) and chemical order parameter S for Fe60Pt40 NPs were as high as 10,200Oe, 17.567emu/g and 0.928, respectively. With the further increase of the Fe content to 80at%, only Fe3Pt phase existed and the Hc of the Fe3Pt NPs decreased drastically to 360Oe. [Copyright &y& Elsevier]