Microscopic and X-Ray Studies on Tungsten Oxide (WO₃)

Abstract

The domain structure of single crystals of tungsten oxide was observed between −130°C and 1200°C. An abrupt change of domain structure was observed at −50°C on cooling and it varied only gradually on heating, as reported (previously). No change was observed at the 910°C transition. The crystal structure was investigated in detail near 910°C. and 1230°C respectively. No change of crystal symmetry except for only slight anomalies of lattice constants was observed at these two transitions. Ferroelectricity or antiferroelectricity and bond structure of this substance were discussed using the result of observations, and it was stressed that these would be in an intimate relation with each other.