Structure of ZrV{sub 2}O{sub 7} from -263 to 470{degrees}C

Journal Article · Mon Sep 01 04:00:00 EDT 1997 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1997.7474· OSTI ID:570220

Khosrovani, N; Sleight, A W ^[1]; Vogt, T ^[2]

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1. Oregon State Univ., Corvallis, OR (United States)
2. Brookhaven National Lab., Upton, Long Island, NY (United States)

High-resolution neutron powder diffraction data were used to analyze the structure of ZrV{sub 2}O{sub 7} at 236{degrees}C was also refined using X-ray powder diffraction data. The thermal expansion is positive below about 100{degrees}C but becomes strongly negative above this temperature. Data from 88 to 470{degrees}C were refined using a 8.8 {angstrom} cubic Z = 4 cell in space group Pa{bar 3}. All V-O-V angles are 180{degrees} on an average in this structure. Data from -263 to 66{degrees}C were refined with a 26.3 {angstrom}, Z = 108 cell still in space group Pa{bar 3}. 89% of the V-O-V linkages are bent to about 160{degrees} but symmetry to be 180{degrees} on average. The strong negative thermal expansion of ZrV{sub 2}O{sub 7} above 100{degrees}C is attributed to the transverse thermal motion of oxygen atoms in the metal-oxygen-metal linkages. These thermal motions can occur only by changing the shape of the polyhedra; thus, the occurrence of negative thermal expansion for cubic AM{sub 2}O{sub 7} compounds is strongly correlated with the rigidity of the AO{sub 6} octahedra and MO{sub 4} tetrahedra.

• OSTI ID: 570220
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 132; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
INTERATOMIC DISTANCES
MOLECULAR STRUCTURE
NEUTRON DIFFRACTION
SYMMETRY
THERMAL EXPANSION
VANADIUM OXIDES
X-RAY DIFFRACTION
ZIRCONIUM OXIDES