Correlation between optical constants and crystal chemical parameters of ZrW{sub 2}O{sub 8}

Journal Article · Thu Oct 15 00:00:00 EDT 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.07.035· OSTI ID:21372343

Shannon, Robert D ^[1]; Medenbach, Olaf ^[2]; Bousquet, Eric; Ghosez, Philippe ^[3]

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1. Geological Sciences/CIRES, University of Colorado, Boulder, CO 80309 (United States)
2. Institut fuer Mineralogie, Fakultaet fuer Geowissenschaften, Ruhr-Universitaet Bochum, Universitaetsstrasse 150, D-44780 Bochum (Germany)
3. Departement de Physique, Universite de Liege, B-5, B-4000 Sart Tilman (Belgium)

The refractive indices of ZrW{sub 2}O{sub 8}, measured at wavelengths of 435.8-643.8 nm, were used to calculate n{sub D} at lambda=589.3 nm and n{sub i}nfinity at lambda=infinity from a one-term Sellmeier equation. Refractive indices, n{sub D} and dispersion values, A, are, respectively, 1.8794 and 114x10{sup -16} m{sup 2}. The high dispersion, relative to other molybdates, tungstates and Zr-containing compounds, is attributed to the low value of E{sub o}=7.7 eV and mean cation coordination number. Total electronic polarizabilities, alpha{sub total}, were calculated from n{sub i}nfinity and the Lorenz-Lorentz equation. The unusually large difference between the observed polarizability of 20.087 A{sup 3} and the calculated total polarizability alpha{sub T} of 17.59 A{sup 3} (DELTA=+12.4%) is attributed to (1) a large M-O-W angle, (2) a high degree of W 5d-O{sub (terminal)} 2p and Zr nd-O 2p hybridization, and (3) unusually high oxygen displacement factors, B(O), normalized to B(W). - Graphical abstract: Refractive indices of ZrW{sub 2}O{sub 8}, measured at lambda=435.8-643.8 nm and a one-term Sellmeier equation allow the determination of n{sub D} (lambda=589.3 nm) of 1.8794 and a dispersion value, A, of 114x10{sup -16} m{sup 2}. The unusually large difference between the observed ZrW{sub 2}O{sub 8} polarizability of 20.087 A{sup 3} and the calculated total polarizability alpha{sub T} of 17.59 A{sup 3} (DELTA=+12.4%) is attributed to (1) a large M-O-W angle, (2) a high degree of W 5d-O{sub (terminal)} 2p and Zr nd-O 2p hybridization, and (3) unusually high oxygen displacement factors, B(O), normalized to B(W).

• OSTI ID: 21372343
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 10 Vol. 182; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CATIONS
CHARGED PARTICLES
COORDINATION NUMBER
CRYSTALS
ELECTRICAL PROPERTIES
ELEMENTS
ENERGY RANGE
EV RANGE
EV RANGE 01-10
IONS
MOLYBDATES
MOLYBDENUM COMPOUNDS
NONMETALS
OPTICAL DISPERSION
OPTICAL PROPERTIES
OXYGEN
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POLARIZABILITY
REFRACTIVE INDEX
REFRACTORY METAL COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TUNGSTATES
TUNGSTEN COMPOUNDS
ZIRCONIUM COMPOUNDS
ZIRCONIUM TUNGSTATES