Abstract
Isolated monodisperse L10 FePt nanoparticles coated by carbon were obtained by adding enough surfactants that decomposed into carbon after the chemical synthesis and postannealing of the A1 FePt nanoparticles. The effect of isolation between FePt nanoparticles on the phase transition temperature and magnetic properties has been studied systematically by thermal, magnetic, and structural characterizations and analyses. It was found that the A1 to L1 0 phase transition temperature is dependent sensitively on the amount of isolation medium. The transition temperature shift reaches 150-200°C from nonisolated particle assemblies to completely isolated particles, which may be attributed to the high activation energy of the phase transformation for the isolated particles.
Original language | English (US) |
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Article number | 4808146 |
Pages (from-to) | 437-443 |
Number of pages | 7 |
Journal | IEEE Transactions on Nanotechnology |
Volume | 8 |
Issue number | 4 |
DOIs | |
State | Published - Jul 2009 |
Externally published | Yes |
Funding
Manuscript received December 16, 2008; revised February 24, 2009. First published March 31, 2009; current version published July 9, 2009. This work was supported by the US Department of Defense (DoD)/Multidisciplinary University Research Initiative (MURI) Grant N00014-05-1-0497, and by the Center of Nanostructured Materials and Characterization Center for Materials and Biology at the University of Texas at Arlington. The review of this paper was arranged by Associate Editor J. Li.
Keywords
- Isolated L1 FePt nanoparticles
- Magnetic hardening
- Magnetocrystalline anisotropy
- Phase transformation
ASJC Scopus subject areas
- Computer Science Applications
- Electrical and Electronic Engineering