Ferroelectric tungsten trioxide

Journal Article · Sun Jun 01 04:00:00 EDT 1997 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1997.7268· OSTI ID:589009

Woodward, P M; Sleight, A W ^[1]; Vogt, T ^[2]

---

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

The structure of a low-temperature form of tungsten trioxide, {epsilon}-WO{sub 3}, has been determined for the first time. Earlier inconclusive evidence for ferroelectricity in this form is confirmed. There are at least six forms of WO{sub 3}, but {epsilon}-WO{sub 3} is the only form now shown to be acentric. The structure analysis of {epsilon}-WO{sub 3} was based primarily on Rietveld analysis of high-resolution neutron diffraction data obtained at 15 K. Higher resolution synchrotron X-ray diffraction data were used to confirm the space group. This {epsilon}-form of WO{sub 3} is monoclinic with a space group of Pc, a = 5.278 A, b = 5.156 {angstrom}, c = 7.664 {angstrom}, {beta} = 91.762{degrees}, and Z = 4. During the transformation from triclinic {delta}-WO{sub 3} to the monoclinic {epsilon}-WO{sub 3}, no change in the octahedral tilt system occurs, but there are significant shifts in the W atom positions. These W atom shifts result in an enhancement of the long-short bond distance alternation in the [110] direction (the [100] direction of the {delta}-phase), which is related to changes in electrical and optical properties.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 589009
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 131; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
ELECTRICAL PROPERTIES
NEUTRON DIFFRACTION
OPTICAL PROPERTIES
TUNGSTEN OXIDES
X-RAY DIFFRACTION