Jpn. J. Appl. Phys. 45 (2006) pp. L608-L610 |Previous Article| |Table of Contents|
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Letter
Direct Synthesis of Oriented High-Density Islands of L10–FePtCu Alloy at 613 K
Han Wool Ryu1,2,
Hiroshi Naganuma2,
Kazuhisa Sato2 and
Yoshihiko Hirotsu2
1Department of Materials Science and Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
2The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
(Received November 16, 2005; accepted April 23, 2006; published online June 9, 2006)
A low-temperature synthesis of isolated and oriented L10–FePtCu nanoparticles with high-density dispersion has been achieved by a conventional rf magnetron sputtering technique with a single crystal NaCl substrate. Hard magnetic L10-type ordered phase with a coercivity of about 1.4 kOe is directly formed at substrate temperatures as low as 613 K without any post-deposition annealing. With a decrease in sputtering duration, particle size and interparticle distance decrease. These nanoparticles have <100> orientation on the NaCl substrate. The alloy compositional change from particle to particle is quite small. Although the atomic ordering is confirmed even at 563 K, the intensity of the superlattice reflections is very weak. The thermal fluctuation of magnetization becomes prominent in specimens with particle size smaller than about 10 nm in diameter.
URL:
http://jjap.jsap.jp/link?JJAP/45/L608/
DOI: 10.1143/JJAP.45.L608
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