Formation of tungsten oxides in the W-O2 system at temperatures from 2000 to 2500 K and a pressure of 1 Pa

We have identified the main reactions responsible for the formation of (WO 3 ) n ( n = 2–5) oxides. In the range T = 2000–2500 K, all of the (WO 3 ) n oxides result from WO disproportionation or from reactions of WO 2 with the components of the system (W, O 2 , and O). Reactions between WO, WO 2 , and WO 3 , as well as W oxidation and WO 2 disproportionation, yield minor amounts of (WO 3 ) n . W 2 O 6 prevails over the other (WO 3 ) n oxides because of (WO 3 ) n ( n = 3–5) decomposition and reactions between them and other components.