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In Situ HREM Observation of Phase Transformation Process in FePt and FePtCu Nanoparticles

Published online by Cambridge University Press:  26 February 2011

Masatoshi Nakanishi
Affiliation:
Masatoshi_Nakanishi@fujifilm.co.jp, Fuji Photo Film Co., Ltd., 210, Minamiashigara, Kanagawa, 250-0193, Japan
Gen-ichi Furusawa
Affiliation:
genichi_furusawa@fujifilm.co.jp, Fuji Photo Film Co., Ltd., Advanced Core Technology Labolatories, Japan
Kokichi Waki
Affiliation:
Kokichi_Waki@fujifilm.co.jp, Fuji Photo Film Co., Ltd., Advanced Core Technology Labolatories, Japan
Yasushi Hattori
Affiliation:
Yasushi_Hattori@fujifilm.co.jp, Fuji Photo Film Co., Ltd., Advanced Core Technology Labolatories, Japan
Takeo Kamino
Affiliation:
kamino-takeo@naka.hitachi-hitec.com, Hitachi High-Technologies Corporation, Naka Application Center, Japan
Katsuhiro Sasaki
Affiliation:
khsasaki@hix.nagoya-u.ac.jp, Nagoya University, Department of Quantum Engineering, Japan
Kotaro Kuroda
Affiliation:
Kuroda@nagoya-u.jp, Nagoya University, Department of Quantum Engineering, Japan
Hiroyasu Saka
Affiliation:
saka@nagoya-u.jp, Nagoya University, Department of Quantum Engineering, Japan
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Abstract

The processes of phase transformation in individual nanoparticles of FePt and FePtCu synthesized by the reverse micelle method, which are chemically homogeneous and monodisperse, have been investigated by an in-situ HREM observation in a FE-TEM. Polycrystalline FePt particles, initially of chemically disordered face-centered cubic phase (A1) were reconstructed into A1 single crystals between 25 °C and 650 °C, followed by phase transformation from A1 to chemically ordered face-centered tetragonal phase (L10) which began between 650 °C and 680 °C. The coalescence began concurrently with phase transformation, i. e., between 650 °C and 680 °C. They turned to be a round-shaped L10 particle between 680 °C and 720 °C. The single crystal formation, the phase transformation from A1 to L10, the coalescence and the round-shaped particle formation were also observed in the FePtCu nanoparticles. The temperatures of single crystal formation, phase transformation (and coalescence) and round-shaped particle formation of the FePtCu nanoparticles were between 25 °C and 500 °C, between 550 °C and 600 °C and between 600 °C and 650 °C, respectively. These temperatures were substantially lower than those for the FePt nanoparticles.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

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References

1 Weller, D., Moser, A., Folks, L., Best, M. E., Lee, W., Toney, M. F., Schwickert, M., Thiele, J., Doerner, M. F., IEEE Trans. Magn. 36, 10 (2000).Google Scholar
2 Sun, S., Murray, C. B., Weller, D., Folks, L., Moser, A., Science 287, 1989 (2000).Google Scholar
3 Harrell, W., Nikles, D. E., Kang, S. S., Sun, X. C., Jia, Z., J. Magn. Soc. Japan 28, 847 (2004).Google Scholar
4 Waki, K., Furusawa, G., Ogawa, K., Hattori, Y., Fujifilm Research & Development 49, 70 (2004).Google Scholar
5 Kamino, T., Saka, H., Microsc. Microanal. Microstr. 3, 393 (1997).Google Scholar