Title

The Defect Structure and Bonding of Zirconium Nitride Containing Excess Nitrogen

Abstract

Zirconium nitride, containing 2.0 wt % Hf, is found to have a 25 = 4.57560 ± 0.00005 A (refraction correction included) and a linear thermal expansion coefficient α = 5.28 × 10 -6 deg -1 (10-60°). Its composition is (Zr, 2% Hf) 0.95 ± 0.03N, experimental density d 25° = 6.884 ± 0.003 g cm -3 (the X-ray density of the stoichiometric compound is 7.284 g cm -3). The unit cell contains 3.913 molecules with 3.5% of all sites (8/unit cell) vacant in the cationic and 1.1% in the anionic (N) sublattice. The excess of N atoms over the stoichiometric formula is 0.19 atom/unit cell. From purely chemical considerations the bonding appears to be more ionic than metallic and may be described as involving various electronic states of nitrogen (N 3-, N 0), imposing a high degree of ionic character on the nitride. However, no quantitative value could be assigned to the degree of ionic bonding.

Department(s)

Materials Science and Engineering

Second Department

Chemistry

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1966 American Chemical Society (ACS), All rights reserved.


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