Synthesis, Diffusion and Ion-Exchange in Open Structure Sodium Tungstates and Ybacu Tungstates

Abstract

AbstractCritical to the effectiveness of any solid state device is the reactivity of its components. In solid state ionics one desires certain atoms or ions to show high ionic mobility; yet, at the same time one does not want these atoms or ions to participate in side reactions. These reactions are a function of the crystalline structure of the material, of the way in which it was synthesized and of it's thermodynamic stability relative to the environment. This paper describes the synthesis of a variety of tungsten oxides which exhibit ionic mobility, and the determination of their crystalline structure and reactivity. The reactivity of the 123 superconductor with tungsten oxides is described in terms of the phases formed; none of these phases exhibited superconductivity. Both of these structurally related materials react with lithium and oxygen in a reversible manner, and these reactions are critically important in determining their properties and potential commercial application.