Crystal structure and high-pressure studies of WAl{sub 2}, an aluminide crystallizing with the CrSi{sub 2} structure type
- Laboratory of Crystallography, Department of Materials, ETH, Zurich 8093 (Switzerland)
The novel intermetallic compound WAl{sub 2} crystallizes with space group P6{sub 4}22 and lattice parameters a=4.7422(1) A, c=6.6057(2) A. The crystal structure was solved from single-crystal X-ray diffraction data. WAl{sub 2} was found to be the first aluminide that is isotypic with CrSi{sub 2}. A high-pressure powder X-ray diffraction study showed its stability up to at least 31.5(1) GPa. The bulk modulus was calculated by fitting a third-order Birch-Murnaghan equation of state to the pressure-volume data as K{sub 0}=168(11) GPa and its pressure derivative K'=7.7(1.0). Partially covalent bonding between W and Al atoms was indicated by means of the electron localization function (ELF) and explains the anisotropic compression behavior. Quantum chemical calculations identify WAl{sub 2} as a potential high-temperature phase. - Graphical abstract: The novel compound WAl{sub 2} is the first aluminide crystallizing with the CrSi{sub 2} structure type. This compound is stable up to high pressures of at least 31.5 GPa. The chemical bonding analysis by means of the electron localization function (ELF) reveals a partially covalent bonding being responsible for the anisotropic compression behavior.
- OSTI ID:
- 21212055
- Journal Information:
- Journal of Solid State Chemistry, Vol. 181, Issue 10; Other Information: DOI: 10.1016/j.jssc.2008.06.053; PII: S0022-4596(08)00347-2; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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