Synthesis of face-centered tetragonal FePt nanoparticles and granular films from Pt@Fe2O3 core-shell nanoparticles.

Academic Article

Abstract

  • This paper describes a new approach for making face-centered tetragonal (fct) FePt nanoparticles with a diameter of 17 nm and granular films from Pt@Fe2O3 core-shell nanoparticle precursors. The core-shell nanoparticles were converted to fct FePt through a reduction and alloy formation process at enhanced temperatures. The Fe and Pt elemental analysis was conducted on both individual nanoparticles and granular films using energy-dispersive X-ray (EDX) spectroscopy. Our convergent evidence from selected area electron diffraction (SAED), powder X-ray diffraction (PXRD), and EDX analysis indicates that the final products are fct FePt alloys. The fct FePt films have coercivities of 8.0-9.1 kOe at 5 K and 7.0 kOe at 300 K measured by a SQUID magnetometer. These values depend on the conversion temperatures of Pt@Fe2O3 nanoparticles. Unlike the previously synthesized disordered face-centered cubic (fcc) FePt nanoparticles with diameters of 4-6 nm (Sun, S. H.; Murray, C. B.; Weller, D.; Folks, L.; Moser, A. Science 2000, 287, 1989), the FePt nanoparticles presented in this work not only possess the preferred fct phase but also are in a size range that is expected to be ferromagnetic and have high coercivity, which is important to the practical applications in ultrahigh density data storage media and magnetic nano devices.
  • Authors

  • Teng, Xiaowei
  • Yang, Hong
  • Status

    Publication Date

  • November 26, 2003
  • Has Subject Area

    Keywords

  • Bioengineering
  • Nanotechnology
  • Digital Object Identifier (doi)

    Pubmed Id

  • 14624605
  • Start Page

  • 14559
  • End Page

  • 14563
  • Volume

  • 125
  • Issue

  • 47