Studies in Crystalline and Amorphous Structures in PbO-V₂O₅-P₂O₅

Abstract

<p>The crystal structures of PbV₂O₆ and α-VPO₅, both from within the glass-forming region of PbO-V₂O₅-P₂O₅, have been determined by X-ray methods to help provide models for the local structure of the glass. A temperature dependent displacive disordering of oxygen atoms is found in α-VPO₅. A specimen has been studied which is still ordered at room temperature but appears to be vanadium rich.</p> <p>X-ray scattering intensities, measured for five compositions of V₁₊ᵪP₁₋ᵪO₅ glass, are compared with a model for the local structure of the glass based upon structural features from a-VPO₅. Available data on the physical properties of the glass, such as density and electrical conductivity, are discussed in relation to the proposed structural model.</p> <p>Methodological problems of X-ray scattering from glass, involved with Compton scattering and multiple scattering, are discussed.</p>