title: Synthesis of magnetic nanocomposites and alloys from platinum-iron oxide core-shell nanoparticles.
abstract: This paper presents a systematic study on the generation of iron platinum-containing magnetic nanocomposites and alloys from Pt@Fe(2)O(3) core-shell nanoparticle precursors. These core-shell nanoparticles were made using a sequential synthetic approach. They could form FePt alloys and alloy-containing nanocomposites through a solid-state reaction at >400 °C. The chemical compositions of FePt alloys were controllable by using Pt@Fe(2)O(3) core-shell nanoparticles that had the designed Pt core diameter and iron oxide shell thickness. We show that face-centred tetragonal (fct) FePt@Fe core-shell nanoparticles could be made from Pt@Fe(2)O(3) core-shell nanoparticles with 5% hydrogen in argon (v/v). Furthermore, various FePt alloys and alloy-containing nanocomposites including metastable intermediate phases could be obtained. The materials were characterized by high resolution scanning transmission electron microscopy (HR-STEM), energy dispersive x-ray (EDX) spectroscopy, powder x-ray diffraction (PXRD), parallel electron energy loss spectroscopy (PEELS), and superconducting quantum interference device (SQUID) magnetometry. These materials could have potential applications as permanent hard magnets and data storage media.
authors: Department of Chemical Engineering, Gavett Hall 253, University of Rochester, Rochester, NY 14627, USA.
authors: Xiaowei
authors: X
authors: Teng
authors: Hong
authors: H
authors: Yang