Hostname: page-component-8448b6f56d-c4f8m Total loading time: 0 Render date: 2024-04-19T15:31:59.281Z Has data issue: false hasContentIssue false

Athermal Fracture of Covalent Bonds

Published online by Cambridge University Press:  15 February 2011

J. J. Gilman*
Affiliation:
Materials Science and Engineering, UCLA, Los Angeles, CA 90095
Get access

Abstract

Most fracture is athermal. Either because it occurs at low temperatures; or because it occurs too fast for thermal activation to be effective. Thus it must be directly activated by applied stresses. This can occur via quantum tunneling when the chemical bonding of a solid resides in localized (covalent) bonds. Then applied stresses can cause the bonding electrons to become delocalized (anti-bonded) through quantum tunneling. That is, the bonds become broken. The process is related to the Zener tunneling process that is thought to be responsible for dielectric breakdown in semiconductors. Under a driving force, bonding electrons tunnel at constant energy from their bonding states into anti-bonding states through the forbidden gap in the bonding energy spectrum.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Gilman, J. J. and Tong, H. S., Quantum Tunneling as an Elementary Fracture Process, J. Appl. Phys., 42, 3479 (1971).Google Scholar
2. Doremus, R. H., Glass Science, Second Edition, p. 178182, John Wiley & Sons, New York (1994).Google Scholar
3. Keyes, R. W., Bonding and Antibonding Potentials in Group-IV Semiconductors, Phys. Rev. Lett., 34, 1334 (1975)Google Scholar
4. Zener, C., A Theory of the Electrical Breakdown of Solid Dielectrics, Proc. Roy. Soc. (London), 145, 523 (1934).Google Scholar
5. Ridley, R. K., Quantum Processes in Semiconductors, p.50, Clarendon Press, Oxford (1982).Google Scholar
6. Bell, R. P., The Tunnel Effect in Chemistry, Chapman and Hall, London (1980).Google Scholar
7. Zhurkov, S. N. and Tomashevskii, E. E., in Physical Basis of Yield and Fracture, Institute of Physics, Conf. Series #1, p. 200, Oxford (1966).Google Scholar
8. Wiederhorn, S. M., J. Am. Ceram. Soc., 53, 543 (1970).Google Scholar
9. Taylor, N. W., J. Appl. Phys., 18, 943 (1947).Google Scholar
10. Glathart, J. L. and Preston, F. W., J. Appl. Phys., 17,189 (1946);Google Scholar
also, Baker, T. C. and Preston, F. W., J. Appl. Phys., 17, 170 (1946).Google Scholar
11. Pavelchek, E. K. and Doremus, R. H., J. Non-Cryst. Solids, 20, 305 (1976)Google Scholar
12. Crist, B., Annu. Rev. Mater. Sci., 25, 295 (1995).Google Scholar