Violet Tungsten Oxide
Violet Tungsten Oxide, which is short for VTO, is a kind of tungsten oxide. Violet tungsten oxide is powder shaped and violet displayed.
Violet tungsten oxide is a finely divided violet crystalline powder. It is produced by rotary calcining ammonium paratungstate at closely controlled temperatures in a reducing atmosphere. CTOMS produces two standard grades differing mainly in oxygen content. Violet tungsten oxide is used primarily for the production of tungsten metal powder and tungsten carbide.
Violet tungsten powder is the most important precursor in the line from oxide to W and WC powder. The colour varies between deep dark purple to violet. Also the VTO particles are pseudomorphous to the original APT crystals, as described for tungsten trioxide.