Lattice Defects and Plastic Deformation of CoSi2


Current knowledge of the properties of vacancies and the slip behavior and mechanisms of CoSi2 is reviewed based on the results of our recent studies on CoSi2. The concentration of thermal vacancies in CoSi2 is much higher than that in ordinary metals and alloys with melting points comparable with that of CoSi2. Vacancy defects are easily retained in CoSi2 even after air cooling from high temperatures. An annealing stage observed at around 310 K after electron irradiation is concluded to occur by the migration of vacancies to form secondary defects. Peculiar phenomena recently reported on CoSi2 such as an anisotropy of electrical resistivity and the climbing of dislocations at room temperature can be understood on the basis of the current knowledge of defect properties. Slip in CoSi2 occurs along <100> on {001} at low temperatures. The selection of {001}<100> as the primary slip system in CoSi2 can be interpreted in terms of high covalency of Co-Si bonding. a<100> dislocations have a strong tendency to align along their edge orientation and are dissociated into two a / 2<100> partial dislocations separated by a stacking fault on {001}. {001}<100> slip is augmented by {111}<110> and {110}<110> slip at high temperatures. Thermal activation analysis of deformation indicates that while deformation at low temperatures is controlled by the Peierls mechanism, the greatly increased concentration of thermal vacancies influence the mobility of dislocations at high temperatures.

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  1. 1.

    D.L. Anton and D.M. Shah, in High-Temperature Ordered Intermetallic Alloys III, edited by C.T. Liu, A.I. Taub, N.S. Stoloff and C.C. Koch (Mater. Res. Soc. Proc. 133, Pittsburgh, PA, 1989)p.361.

    Google Scholar 

  2. 2.

    R.W. Sauer and E.J. Freise, in Anisotropy in Single-Crystal Refractory Compounds, Vol.1, edited by F.W. Vahldiek and S.A. Merson (Plenum, New York, 1968) p.459.

  3. 3.

    S. Takeuchi, T. Hashimoto and T. Shibuya, in Intermetallic Compounds - Structure and Mechanical Properties-, edited by O. Izumi (Japan Inst. Metals, 1991) p.645; J. Mater. Sci. 27, 1380 (1992).

  4. 4.

    K. Ito, H. Inui, T. Hirano and M. Yamaguchi, Mater. Sci. Eng. A, 152, 153 (1992).

    Article  Google Scholar 

  5. 5.

    P. Anongba and S. Steincmann, presented at 1991 Colloque Plastcité at Metz.

  6. 6.

    K. Suzuki and S. Takeuchi, to be published in Intcrmetallics, 1 (1992).

  7. 7.

    B.M. Ditchek, J. Cryst. Growth, 69, 207 (1984).

    CAS  Article  Google Scholar 

  8. 8.

    T. Hirano and M. Kaise, J. Appl. Phys., 68, 627 (1990).

    CAS  Article  Google Scholar 

  9. 9.

    D.M. Shah, D. Berczik, D.L. Anton and R. Hecht, Mater. Sci. Eng. A, 155, 45 (1992).

    Article  Google Scholar 

  10. 10.

    Y. Shirai and M. Yamaguchi, Mater. Sci. Eng. A, 152, 173 (1992).

    Article  Google Scholar 

  11. 11.

    See for example, J. Takamura, Y. Shirai, K. Furukawa and F. Nakamura, Mater. Sci. Forum, 15–18, 809 (1987).

    Article  Google Scholar 

  12. 12.

    Y. Ito, Y. Shirai, Y. Yamada and M. Yamaguchi, in this proceedings.

  13. 13.

    A.G Balogh, L. Bottyan, G. Braucr, I. Dezsi and B. Molnar, J. Phys. F, 16, 1725 (1986).

    CAS  Article  Google Scholar 

  14. 14.

    K. Tanaka, H. Numakura and M. Koiwa, private communication.

  15. 15.

    A.G. Evans and P.L. Pratt, Phil. Mag., 21, 951 (1970).

    CAS  Article  Google Scholar 

  16. 16.

    T.S. Liu and C.H. Li, J. Appl. Phys., 35, 3325 (1964).

    CAS  Article  Google Scholar 

  17. 17.

    P.E. Irving and C.J. Beevers, J. Mater. Sci., 7, 23 (1972).

    CAS  Article  Google Scholar 

  18. 18.

    K.G. Barraclogh and C.J. Beevers, J. Mater. Sci., 4, 518 (1969).

    Article  Google Scholar 

  19. 19.

    S. Geller and V.M. Wolontis, Acta Crystallogr., 8, 83 (1955).

    CAS  Article  Google Scholar 

Download references


This work was supported by Grant-in-Aid for Scientific Research on the Priority Area “Intermetallic Compounds as New High Temperature Structural Materials” from the Ministry of Education, Science and Culture, Japan and in part by the research grant from the R & D Institute of Materials and Composites for Future Industries and the NEDO International Joint Research Grant for the Intermetallics Research Team.

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Yamaguchi, M., Shirai, Y. & Inui, H. Lattice Defects and Plastic Deformation of CoSi2. MRS Online Proceedings Library 288, 131–139 (1992).

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