Abstract
FePt nanoparticles with a size of 3 nm and thermally stable room-temperature ferromagnetism are investigated. The monodisperse nanoparticles were prepared by chemical synthesis and a salt-matrix annealing technique. Structural and magnetic characterizations confirmed the phase transition from the disordered face-centered cubic structure to the L 10 structure with the chemical ordering parameter of 0.62±0.05. Analysis in blocking temperature and fitting of temperature dependence of switching field reveals that the transformed 3 nm nanoparticles have a magnetic anisotropy constant of (2.8±0.2) × 106 J m3, smaller than those for the bigger particles and the fully ordered L 10 bulk phase.
Original language | English (US) |
---|---|
Article number | 043913 |
Journal | Journal of Applied Physics |
Volume | 102 |
Issue number | 4 |
DOIs | |
State | Published - 2007 |
Externally published | Yes |
Funding
This work was supported by U.S. DoD/MURI Grant N00014-05-1-0497 and DARPA through ARO under Grant No DAAD 19-03-1-0038. Work at the Ames Laboratory was supported by the Department of Energy-Basic Energy Sciences under Contract No. DE-AC02-07CH11358. Work at the University of Nebraska was supported by NSF-MRSEC and NCMN.
ASJC Scopus subject areas
- General Physics and Astronomy