Abstract
Bimagnetic FePt/ Fe3 O4 nanoparticles with core/shell or heterodimer structure have been prepared using a sequential synthetic method. The dimension of both FePt and Fe3 O4 was tuned by varying the synthesis parameters. The as-synthesized bimagnetic nanoparticles were superparamagnetic at room temperature. After being annealed in a reducing atmosphere, the FePt/ Fe3 O4 bimagnetic nanoparticles were converted to a hard magnetic nanocomposite with enhanced energy products due to the exchange coupling between the hard and soft magnetic phases. It was found that the exchange coupling in nanocomposites made from the core/shell nanoparticles is stronger than that from the heterodimer nanoparticles. By tuning the dimensions of the FePt and Fe3 O4 phases, the energy product up to 17.8 MGOe was achieved in the annealed nanocomposites, which is 36% higher than the isotropic single-phase FePt counterpart.
Original language | English (US) |
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Article number | 014303 |
Journal | Journal of Applied Physics |
Volume | 105 |
Issue number | 1 |
DOIs | |
State | Published - 2009 |
Externally published | Yes |
ASJC Scopus subject areas
- General Physics and Astronomy