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Defect Properties and Magnetism in B2-type CoFe Alloys

Published online by Cambridge University Press:  11 February 2011

Keiichi Harada
Affiliation:
Department of Materials Science, College of Integrated Arts and Sciences, Osaka Prefecture University, Sakai, 599–8531, Japan
Hiroki Ishibashi
Affiliation:
Department of Materials Science, College of Integrated Arts and Sciences, Osaka Prefecture University, Sakai, 599–8531, Japan
Mineo Kogachi
Affiliation:
Department of Materials Science, College of Integrated Arts and Sciences, Osaka Prefecture University, Sakai, 599–8531, Japan
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Abstract

Point defect properties have been studied for B2-type Co1-cFec alloys (0.4 ≤ c ≤ 0.6 ) by X-ray diffraction and density measurements. The lattice constant increases with increase in composition c and indicates a distinct change in the slope beyond c = 0.5. Further, it shows a decrease with increase in quenching temperature. The obtained vacancy concentration is very low for any composition and temperature concerned. Thus, it can be concluded that defect type in B2 CoFe is an antisite atom. The change in the lattice constant with quenching temperature can be related to the long-range order (LRO): it is well approximated by a linear form with respect to square of the LRO parameter. CoFe alloys in both B2 and higher temperature A2 phase regions show ferromagnetism. Observed results are discussed taking a correlation between the defect structure and the magnetic behavior into account.

Type
Research Article
Copyright
Copyright © Materials Research Society 2003

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References

REFERENCES

1. Kogachi, M., High Temp. Mater. Process. 18, 269 (1999).Google Scholar
2. Kogachi, M., Minamigawa, S. and Nakahigashi, K., Acta Metall. Mater. 40, 1113 (1992).Google Scholar
3. Kogachi, M., Tanahashi, T., Shirai, Y. and Yamaguchi, M., Scripta Mater. 40, 243 (1996).Google Scholar
4. Kogachi, M. and Haraguchi, T., Mater. Sci. Engineer. A230, 124 (1997).Google Scholar
5. Haraguchi, T., Hori, F., Oshima, R. and Kogachi, M., Intermetallics 9, 763 (2001).Google Scholar
6. Ishibashi, H., Kogachi, M., Ohba, T., Ren, X. and Otsuka, K., Mater. Sci. Engineer. A329–331, 568 (2002).Google Scholar
7. Haraguchi, T. and Kogachi, M., Mater. Sci. Engineer. A329–331, 402 (2002).Google Scholar
8. Nagpal, P. and Baker, I., Metall. Trans. A21, 2281 (1990).Google Scholar
9. Lyashenko, B.G., Litvin, D.F., Puzey, I.M. and Abov, J.G., J. Phys. Soc. Jpn. 17, Suppl. B-III, 49 (1962).Google Scholar
10. Tahara, Y., Shinohara, K., Kuroki, H. and Eguchi, T., J. Jpn. Inst. Metals. 39, 105 (1975).Google Scholar
11. Shiga, M., A.I.P. Conf. Proc. No. 18, Magnetism and Magnetic Materials, 463 (1973).Google Scholar
12. Collins, M.F. and Forsyth, J.B., Phil. Mag. 8, 401 (1963).Google Scholar
13. Bardos, D.I., J. Appl. Phys. 40, 1371 (1969).Google Scholar