Polymeric Gaseous Species in the Sublimation of Tungsten Trioxide

Abstract

Mass spectrometric study of the gaseous species effusing from a Knudsen cell filled with WO₃ has shown that WO₃(s) sublimes to form the gaseous molecules W₃O₉, W₄O₁₂, and W₅O₁₅. From the measured partial pressures for these species and their variations with temperature, ΔH, ΔF⁰, and ΔS⁰ of sublimation are obtained.