Advertisement

Journal of Materials Science

, Volume 20, Issue 2, pp 736–755 | Cite as

Load relaxation studies of germanium

  • S. -W. Chiang
  • D. L. Kohlstedt
Article

Abstract

A series of compressive load relaxation experiments were conducted on germanium single crystals in the temperature range 400 to 885° C. The curvature of the logσ-log\(\dot \in \) data obtained from load relaxation tests changes from concave upward to concave downward as the test temperature increases at fixed stress level, or as the strain level increases at fixed temperature. At intermediate temperatures, ∼600° C, the transition from concave upward to concave downward curvature happens on a single relaxation curve. These observations are consistent with the two-branch rheological model proposed by Hart to explain the deformation behaviour of metals and were analysed in terms of this model. The transition from concave upward to concave downward curvature could be moved to higher temperature by doping germanium with gallium, which decreases the dislocation glide velocity relative to that in pure germanium. The transition could be shifted to lower temperature by compressing samples along [1\(\bar 1\)1] rather than [1\(\bar 1\)0] because the [1\(\bar 1\)1] orientation favours cross-slip while the [1\(\bar 1\)0] orientation does not. Dislocation dipoles and straight dislocations dominated the microstructure of samples which had concave upward logσ-log\(\dot \in \) curves, while well-developed dislocation cell structures dominated the microstructure of samples which yielded concave downward curves. The observed changes in the curvature of the load relaxation curves and the dislocation structure both indicate the increased importance of dislocation climb with increasing temperature. When compared through the Orowan equation, the load relaxation results are in good agreement with published stress-dislocation velocity data.

Keywords

Germanium Relaxation Curve Dislocation Climb Dislocation Dipole Load Relaxation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    H. Alexander andP. Haasen,Solid State Phys. 22 (1968) 27.Google Scholar
  2. 2.
    A. R. Lang,J. Appl. Phys. 29 (1958) 597.Google Scholar
  3. 3.
    H. Schaumburg,Phil. Mag. 25 (1972) 1429.Google Scholar
  4. 4.
    J. R. Patel andP. E. Freeland,J. Appl. Phys. 42 (1971) 3298.Google Scholar
  5. 5.
    R. L. Bell andW. Bonfield,Phil. Mag. 9 (1964) 9.Google Scholar
  6. 6.
    P. Penning andG. De Wind,Physica 25 (1959) 765.Google Scholar
  7. 7.
    D. J. H. Cockayne, I. L. F. Ray andM. J. Whelan,Phil. Mag. 20 (1969) 1265.Google Scholar
  8. 8.
    I. L. F. Ray andD. J. H. Cockayne,Proc. Roy. Soc. A 325 (1971) 543.Google Scholar
  9. 9.
    Idem, J. Microsc. 98 (1973) 170.Google Scholar
  10. 10.
    F. Häussermann andH. Schaumburg,Phil. Mag. 27 (1973) 745.Google Scholar
  11. 11.
    A. Gomez, D. J. H. Cockayne, P. B. Hirsch andV. Vitek,ibid. 31 (1975) 105.Google Scholar
  12. 12.
    C. B. Carter andP. B. Hirsch,ibid. 35 (1977) 1509.Google Scholar
  13. 13.
    K. Wessel andH. Alexander,ibid. 35 (1977) 1523.Google Scholar
  14. 14.
    H.-J. Möller,Acta Metall. 26 (1978) 963.Google Scholar
  15. 15.
    A. S. Argon (ed.), “Constitutive Equations in Plasticity” (MIT Press, Cambridge, Mass., 1975).Google Scholar
  16. 16.
    E. W. Hart,Trans. J. Eng. Mater. Technol. 98 (1976) 193.Google Scholar
  17. 17.
    I. Lerner, S.-W. Chiang andD. L. Kohlstedt,Acta Metall. 27 (1979) 1187.Google Scholar
  18. 18.
    I. Lerner andD. L. Kohlstedt,J. Amer. Ceram. Soc. 64 (1981) 105.Google Scholar
  19. 19.
    Idem, Acta Metall. 30 (1982) 225.Google Scholar
  20. 20.
    E. Billig,Proc. Roy. Soc. A235 (1956) 37.Google Scholar
  21. 21.
    W. G. Johnston,J. Appl. Phys. 33 (1962) 2716.Google Scholar
  22. 22.
    J. R. Patel andA. R. Chaudhuri,ibid. 34 (1963) 2788.Google Scholar
  23. 23.
    D. Lee andE. W. Hart,Metall. Trans. 2 (1971) 1245.Google Scholar
  24. 24.
    E. W. Hart andH. D. Solomon,Acta Metall. 21 (1973) 295.Google Scholar
  25. 25.
    H. Yamada andC. Y. Li,Metall. Trans. 4 (1973) 2133.Google Scholar
  26. 26.
    Idem, Acta Metall. 22 (1974) 249.Google Scholar
  27. 27.
    F. H. Huang, F. V. Ellis andC. Y. Li,Metall. Trans. 8A (1977) 699.Google Scholar
  28. 28.
    C. Zener andJ. H. Holloman,J. Appl. Phys. 17 (1946) 69.Google Scholar
  29. 29.
    E. W. Hart, C. Y. Li, H. Yamada andG. L. Wire, in “Constitutive Equation in Plasticity”, edited by A. S. Argon (MIT Press, Cambridge, Mass., 1975) p. 149.Google Scholar
  30. 30.
    U. F. Kocks,J. Eng. Mater. Technol. 98 (1976) 76.Google Scholar
  31. 31.
    Idem, in “Constitutive Equations in Plasticity”, edited by A. S. Argon (MIT Press, Cambridge, Mass., 1975) p. 81.Google Scholar
  32. 32.
    R. W. Rohde andJ. C. Swearengen,J. Eng. Mater. Technol. 99 (1977) 59.Google Scholar
  33. 33.
    J. C. Swearengen andR. W. Rohde,Metall. Trans. 8A (1977) 577.Google Scholar
  34. 34.
    O. D. Sherby, R. H. Klundt andA. Miller,ibid. 8A (1977) 843.Google Scholar
  35. 35.
    I. Gupta andJ. C. M. Li,ibid. 1 (1970) 2323.Google Scholar
  36. 36.
    Idem, Mater. Sci. Eng. 6 (1970) 20.Google Scholar
  37. 37.
    E. Orowan,Proc. Phys. Soc. London 52 (1940) 8.Google Scholar
  38. 38.
    W. G. Johnston andJ. J. Gilman,J. Appl. Phys. 30 (1959) 129.Google Scholar
  39. 39.
    A. R. Chaudhuri, J. R. Patel andL. G. Rubin,ibid. 33 (1962) 2736.Google Scholar
  40. 40.
    Idem, ibid. 34 (1963) 240. (1963) 240.Google Scholar
  41. 41.
    S. Takeuchi andA. S. Argon,J. Mater. Sci. 11 (1976) 1542.Google Scholar
  42. 42.
    S. Schafer,Phys. Status Solidi 19 (1967) 297.Google Scholar
  43. 43.
    O. W. Johnson,J. Appl. Phys. 36 (1965) 3247.Google Scholar
  44. 44.
    J. R. Patel,Discuss. Faraday Soc. 38 (1964) 201.Google Scholar
  45. 45.
    A. H. Cottrell, “Dislocations and Plastic Flow in Crystals” (Oxford University Press, London, 1953) p. 140.Google Scholar
  46. 46.
    H. Neuhäuser andH. Flor,Scripta Metall. 12 (1978) 443.Google Scholar
  47. 47.
    J. P. Hirth andJ. Lothe, “Theory of Dislocations” (McGraw Hill, New York, 1968).Google Scholar
  48. 48.
    U. F. Kocks, A. S. Argon andM. F. Ashby,Prog. Mater. Sci. 19 (1975) 64.Google Scholar
  49. 49.
    P. R. Bevington, “Data Reduction and Error Analysis for the Physical Sciences” (McGraw-Hill, New York, 1969) p. 237.Google Scholar
  50. 50.
    Y. A. Burenkov, S. P. Nikanorov andA. V. Stepanov,Sov. Phys. Solid State 12 (1971) 1940.Google Scholar
  51. 51.
    R. F. S. Hearmon,Rev. Modern Phys. 18 (1946) 409.Google Scholar
  52. 52.
    G. L. Wire, H. Yamada andC. Y. Li,Acta Metall. 22 (1974) 505.Google Scholar
  53. 53.
    S.-W. Chiang, C. B. Carter andD. L. Kohlstedt,Phil. Mag. 42 (1980) 103.Google Scholar
  54. 54.
    Idem, Scripta Metall. 14 (1980) 803.Google Scholar
  55. 55.
    B. J. Boltaks, in “Diffusion in Semiconductors”, translated by J. I. Carasso, edited by H. J. Goldsmid (Academic Press, New York, 1963) p. 93.Google Scholar
  56. 56.
    H.-J. Moller andP. Haasen,Phys. Status Solidi 33a (1976) K59.Google Scholar
  57. 57.
    R. Labusch,ibid. 10 (1965) 645.Google Scholar
  58. 58.
    J. R. Patel andA. R. Chaudhuri,Phys. Rev. 143 (1966) 601.Google Scholar

Copyright information

© Chapman and Hall Ltd 1985

Authors and Affiliations

  • S. -W. Chiang
    • 1
  • D. L. Kohlstedt
    • 1
  1. 1.Department of Materials Science and EngineeringCornell UniversityIthacaUSA

Personalised recommendations