Phase Transformation and Magnetic Hardening in Isolated FePt Nanoparticles
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Date
2009-07Author
Liu, J. Ping
Rong, Chuan-Bing
Nandwana, Vikas
Poudyal, Narayan
Chaubey, Girija S.
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Show full item recordAbstract
Isolated monodisperseL10 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 L10 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.