Crystal structure and equation of state of cotunnite-type zirconia

Journal Article · Wed Feb 01 04:00:00 EST 1995 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1995.tb08822.x· OSTI ID:79814

Haines, J; Leger, J M; Atouf, A ^[1]

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1. C.N.R.S., Meudon (France). Lab. de Physico-Chimie des Materiaux

Cotunnite-type zirconia was studied by angular-dispersive X-ray diffraction in a diamond anvil cell after laser heating and 18 and 26.7 GPa. The structure, space group Pnam, Z = 4, was refined in situ at several different pressures on decompression and at ambient using the Rietveld method. The nine polyhedral Zr-O distances range from 2.10 to 2.56 {angstrom} at ambient pressure, which represents both an increase in the average and the minimum Zr-O distance relative to the monoclinic and orthorhombic lower-pressure forms. In addition, data obtained on an unheated sample indicate that the irreversible transition to the cotunnite phase began above 25 GPa and 70% conversion was achieved by 48.5 GPa. The compressibility of cotunnite-type zirconia was found to be slightly anisotropic and a Birch-Murnaghan equation-of-state fit of the p-V data yielded a bulk modulus of 332(8) GPa with a first derivative of 2.3(4), which is in good agreement with the value predicted by previous ab initio calculations.

• Sponsoring Organization: USDOE
• OSTI ID: 79814
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 2 Vol. 78; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPRESSIBILITY
CRYSTAL STRUCTURE
EQUATIONS OF STATE
LASERS
POWDERS
PRESSURE DEPENDENCE
TEMPERATURE DEPENDENCE
X-RAY DIFFRACTION
ZIRCONIUM OXIDES