High-Pressure Phases in the System W-O. I. Structure of WO1.09 by HRTEM

Article abstract of DOI:10.1107/S0108768191013630

A new type of tungsten oxide was synthesized from a mixture of W and WO3 by a solid-phase sintering method under high-pressure conditions.The crystal structure of the new oxide WO1.09 was investigated by selected-area electron diffraction and high-resolution transmission electron microscopy (HRTEM).It has the following unit-cell parameters: a=17.16, b=10.32, c=3.78 Angstroem, V=669 Angstroem³, Z=44, ρ=21 (3) g cm^-3, and belongs to the space group Cmm2.The W positions were determined from computer-processed HRTEM structure images.The R-factor minimization procedure was used to refine cationic sites; R'=14.5percent.It is shown that the crystal structure is formed by edge sharing WO3 octahedrally and tetrahedrally coordinated W cations.