Applications of these materials derive from their hardness, high melting points and, in some cases, catalytic and magnetic properties and superconductivity; yet their electronic structure is still something of a mystery.
The field of interstitial compounds is a mature one, with an enormous literature. Nevertheless, a question as fundamental as the nature of their electronic structure remains a topic for lively (sometimes acrimonious) debate today. Moreover, industry has yet to tap more than a few of the myriad technical possibilities of these materials. The most commonly exploited property is their great hardness: tons of the interstitial compound tungsten carbide are produced annually for use in grinding and cutting tools. But other properties have seen little commercial application as yet. To cite a few: as a class, they are refractory, yet metallic, and they often have abnormally low work functions, making them excellent electron emitters. This combination suggests, for example, utility as magnetohydrodynamic channel electrodes. Some interstitial compounds, such as NbN, are superconducting, with transition temperatures second only to such champions as Tungsten carbide and related compounds are moderately good catalysts, able to operate in chemically hostile environments, as may be encountered, for example, in fuel cells. Many are respectable ferro‐ and antiferromagnets. As we will try to indicate, this class of compounds poses fascinating possibilities for the technologist and real challenges for the researcher.
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References
1. L. E. Toth, Transition Metal Carbides and Nitrides, Academic, New York (1971); Refractory Carbides (G. V. Samsonov, ed.) Consultants Bureau, New York (1974); H. J. Goldschmidt, Interstitial Alloys, Plenum, New York (1967); E. K. Storms, The Refractory Carbides, Academic, New York (1967); B. Aronsson, T. Lundstrom, S. Rundqvist, Borides, Silicides, and Phosphides, Wiley, New York (1965); Transition Metal Hydrides (E. L. Muetterties, ed.) Marcel Dekker, New York (1971).
2. E. Rudy, Compendium of Phase Diagram Data (Air Force Materials Laboratory Technical Report 65‐2, Part V, Dayton, Ohio, 1969).
3. A. J. McAlister, J. R. Cuthill, M. L. Williams, R. C. Dobbyn, Proc. Intnl. Sym. X‐ray Spectra and Electronic Structure of Matter (A. Faessler and G. Wiech, eds) Fotodruck Frank OHB, Munich (1973); S. H. Liu, L. Kopp, W. B. England, H. W. Myron, Phys. Rev. B 11, 3463 (1975).https://doi.org/PLRBAQ
6. I. R. Harris, J. P. G. Farr, Hydrogen in Metals, Elsevier Sequoia S. A., Lausanne (1976) reprinted from J. Less‐Common Met. 49, Nos. 1 and 2 (1976); https://doi.org/JCOMAH Proceedings of the International Conference “Hydrogen in Metals,” Jülich, 1972, appearing in Ber. Bunsenges. Phys. Chem. 76 (1972).https://doi.org/BBPCAX
7. R. B. Levy, M. Boudart, Science 181, 547 (1973); https://doi.org/SCIEAS L. H. Bennett, J. R. Cuthill, A. J. McAlister, N. E. Erickson, R. E. Watson, Science 184, 563 (1974) https://doi.org/SCIEAS and 187, 858 (1975); https://doi.org/SCIEAS, Science L. H. Bennett, A. J. McAlister, J. R. Cuthill, N. E. Erickson, R. E. Watson, J. Molecular Catal., 2, 203 (1977).https://doi.org/JMCADS
8. R. E. Watson, L. H. Bennett, in Charge Transfer and Electron Structure of Alloys (L. H. Bennett and R. H. Willens, eds.), The Metallurgical Society, New York (1974).
More about the Authors
Lawrence H. Bennett.
Institute for Materials Research, National Bureau of Standards, Washington D.C..
Archie J. McAlister.
Institute for Materials Research, National Bureau of Standards, Washington D.C..
Richard E. Watson.
Brookhaven National Laboratory.
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November 10, 2025 10:22 AM
This Content Appeared In
Volume 30, Number 9
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