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Mechanisms of Shear-Induced Solid-State Reactions

Published online by Cambridge University Press:  15 February 2011

J. J. Gilman
J. J. Gilman*
Affiliation:
Department of Materials Science and Engineering, University of California at Los Angeles, Los Angeles, California90095
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Abstract

Both experiments and band-structure calculations indicate that shear strains lead to closure of energy band gaps in periodic solids, and closure of the LUMO-HOMO gaps in molecules (this is also expected for non-metallic glasses). It allows athermal and ultrafast mechano-chemical reactions to occur. Simple models account for the phenomena. For periodic solids, shear shortens one axis and extends another. In contrast, hydrostatic compression causes both axes to contract. Thus the former shifts the band gaps oppositely for the two directions, causing a reduction in the minimum gap. For molecules, shear tends to increase the bonding orbitals while decreasing the antibonding orbitals, thereby reducing the LUMO-HOMO gaps. The models are consistent with band structure models for diamond.

Shear-induced gap reductions account for the athermal chemical reactions observed by Bridgman, Enikolopyan, Boldyrev, and others. They account for the ultra-fast reactions that occur in explosives.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 453: Symposium R – Solid State Chemistry of Inorganic Materials , 1996 , 227
Copyright
Copyright © Materials Research Society 1997

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References

REFERENCES

[I] Burdett, J. K., Chemical Bonding in Solids,. Oxford University Press, New York (1995).Google Scholar
[2] Pearson, R. G., Ace. Chem. Res., 26, 250 (1996).Google Scholar
[3] Bridgman, P. W., Phys. Rev., 48, 825 (1935).Google Scholar
[4] Boldyrev, V. V., Jour. Chim. Physique, 83, 821 (1986).Google Scholar
[5] Enikolopyan, N. S., Vol'eva, V. B., Khzardzhyan, A. A. and Ershov, V. V., Doki. Akad. Nauk SSSR, 292, 1165 (1987).Google Scholar
[6] Zharov, A. A., Chapter 7 in High Pressure Chemistry and Physics of Polymers, Ed. by Kovarskii, A. L., CRC Press, Boca Raton, FL (1994).Google Scholar
[7] Armstrong, R. W., Coffey, C. S. and Elban, W. L, p.469 in Advances in Chemical Reaction Dynamics, Ed. by Rentzepsis and Capellos, Reidel, D., New York (1986).Google Scholar
[8] Gilman, J. J., in Metal-Insulator Transitions Revisited. Edwards, P. P. and Rao, C. N. R., Editors, p. 269, Taylor & Francis Ltd., London (1995).Google Scholar
[9] Gilman, J. J., in Metal-Insulator Transitions Revisited., Edwards, P. P, Ramakrishnan, T. V., and Rao, C. N. R., p. xv.Google Scholar
[10] Surh, M. P., Louie, S. G., and Cohen, M. L., Phys. Rev. B, 45, 8239 (1992).Google Scholar
[11] Gilman, J. J., Phil. Mag. B, 67, 207 (1993).Google Scholar
[12] Gilman, J. J., Czech. J. Phys., 45, 913 (1995).Google Scholar
[13] Weigel, C., Messmer, R. P. and Corbett, J. W., Sol. State Comm., 13, 723 (1973).Google Scholar
[14] Fukui, K., Science, 218, 747 (1982).Google Scholar
[15] Politzer, P. and Daiker, K. C., in The Force Concept in Chemistry, Ed. by Deb, B. M., p.294, Van Nostrand Reinhold Company, New York (1981).Google Scholar
[16] Gilman, J. J. and Tong, H. S., J. Appl. Phys., 42, 3479 (1971).Google Scholar