Improvement of magnetic properties of FePt nanoparticles by adding Mn

Abstract

FePtMn nanoparticles were synthesized by the simultaneous reduction of iron acetylacetonate, platinum acetylacetonate, and manganese acetylacetonate with 1,2-hexadecanediol as the reducing reagent in the polyol process. The coercivity of annealed nanoparticles strongly depends on the amount of Mn addition. A maximum coercivity of 19 kOe at room temperature was obtained for (Fe32 Pt68) 87 Mn13 nanoparticles annealed at 700 °C for 1 h. The presence of Mn in the FePt L 10 lattice may induce local strain so the ordering is accelerated. In addition, the high coercivity can presumably be partially related to the local bonding of Pt-Mn (or Fe-Mn) in the L 10 structure. © 2005 American Institute of Physics.