Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Coherent displacement of atoms during ion irradiation

Abstract

Ion irradiation is a common technique of materials processing, as well as being relevant to the radiation damage incurred in nuclear reactors. Early models of the effects of ion irradiation typically assumed that particles undergo two-body elastic collisions1, like billiard balls colliding in three dimensions. Later descriptions invoked such phenomena as localization of kinetic energy, thermalization and localized melting2,3,4. In all these descriptions, the displacement of atoms is chaotic in that slight variations in the ion's trajectory produce completely different, unpredictable sets of atomic displacements5. Here we report molecular-dynamics simulations of high-energy self-bombardment of copper and nickel, in which we see collective displacements of atoms. The high pressures developed in collision cascades centred well below the surface can cause a coherent displacement of thousands of atoms, over tens of atomic planes, in a shear-induced slip motion towards the surface. The mechanism leads to a significant increase in damage production near the surface, characterized by well-ordered islands of adsorbed atoms. Our findings suggest an explanation for some features of radiation damage, as well as for differences between ion and neutron irradiation6.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Shape of adatom island ejected onto the surface by the shear mechanism in one 50-keV cascade in Cu.
Figure 4: Side view of the final positions of all adatoms, interstitials and vacancies formed in the event forming the large adatom islands.
Figure 2: Side view of atoms displaced by more than half a nearest-neighbour distance in a 50-keV Cu cascade event.
Figure 3: Time development of Pz and Nnew in the 50-keV Cu cascade forming the adatom island.

Similar content being viewed by others

References

  1. Moreno Marin, J. C., Conrad, U. & Urbassek, H. M. Fractal structure of collision cascades. Nucl. Instrum. Methods Phys. Res. B 48, 404–407 (1990).

    Article  ADS  Google Scholar 

  2. Diaz de la Rubia, T., Averback, R. S., Benedek, R. & King, W. E. Role of thermal spikes in energetic collision cascades. Phys. Rev. Lett. 59, 1930–1933 (1987).

    Article  ADS  CAS  Google Scholar 

  3. Bacon, D. J. & Diaz de la Rubia, T. Molecular dynamics computer simulations of displacement cascades in metals. J. Nucl. Mater. 216, 275–290 (1994).

    Article  ADS  CAS  Google Scholar 

  4. Averback, R. S. & Diaz de la Rubia, T. in Solid State Physics Vol. 51 (eds Ehrenfest, H. & Spaepen, F.) 281–402 (Academic, New York, (1998)).

    Google Scholar 

  5. Robinson, M. T. The statistics of sputtering. Nucl. Instrum. Methods Phys. Res. B 90, 509–512 (1994).

    Article  ADS  CAS  Google Scholar 

  6. English, C. A. & Jenkins, M. L. Insight into cascade processes arising from cascade collapse. Mater. Sci. Forum. 15–18, 1003–1022 (1987).

    Article  Google Scholar 

  7. Diaz de la Rubia, T. & Gilmer, G. H. Structural transformations and defect production in ion implanted silicon: a molecular dynamics simulation study. Phys. Rev. Lett. 74, 2507–2510 (1995).

    Article  ADS  CAS  Google Scholar 

  8. Nordlund, K., Wei, L., Zhong, Y. & Averback, R. S. Role of electron-phonon coupling on collision cascade development in Ni, Pd and Pt. Phys. Rev. B 57, 13965–13968 (1998).

    Article  ADS  Google Scholar 

  9. Ghaly, M. & Averback, R. S. Effect of viscous flow on ion damage near solid surfaces. Phys. Rev. Lett. 72, 364–367 (1994).

    Article  ADS  CAS  Google Scholar 

  10. Kittel, C. Introduction to Solid State Physics 3rd edn (Wiley, New York, (1968)).

    MATH  Google Scholar 

  11. Nordlund, K. & Averback, R. S. Point defect movement and annealing in collision cascades. Phys. Rev. B 56, 2421–2431 (1997).

    Article  ADS  CAS  Google Scholar 

  12. Fukushima, H., Jenkins, M. L. & Kirk, M. A. On the determination of the nature of defect clusters produced by displacement cascades. Part II. Application of stereo imaging techniques to heavy-ion damage in copper. Phil. Mag. A 75, 1583–1602 (1997).

    Article  ADS  CAS  Google Scholar 

  13. Brown, L. M. & Woolhouse, G. R. The loss of coherency of precipitates and the generation of dislocations. Phil. Mag. 21, 329–345 (1970).

    Article  ADS  CAS  Google Scholar 

  14. Gibson, J. B., Goland, A. N., Milgram, M. & Vineyard, G. H. Dynamics of radiation damage. Phys. Rev. 120, 1229–1253 (1960).

    Article  ADS  CAS  Google Scholar 

  15. Nordlund, K.et al. Defect production in collision cascades in elemental semiconductors and FCC metals. Phys. Rev. B 57, 7556–7570 (1998).

    Article  ADS  CAS  Google Scholar 

  16. Seeger, A. in Radiation Damage in Solids Vol. 1, 101–127 (Int. Atomic Energy Agency, Vienna, (1962)).

    Google Scholar 

  17. Kojima, S.et al. Confirmation of vacancy-type stacking fault tetrahedra in quenched, deformed and irradiated face-centred cubic metals. Phil. Mag. A 59, 519–532 (1989).

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

This work was supported by the Academy of Finland, the US National Science Foundation and the US Department of Energy. Grants of computer time from the Center for Scientific Computing in Espoo, Finland, the National Energy Research Computer Center at Livermore, California, and the National Center for Supercomputing Applications in Champaign, Illinois, are gratefully acknowledged.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to K. Nordlund.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Nordlund, K., Keinonen, J., Ghaly, M. et al. Coherent displacement of atoms during ion irradiation. Nature 398, 49–51 (1999). https://doi.org/10.1038/17983

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/17983

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing