Determination of oxygen activities in melts and solid materials by solid electrolyte cells

Abstract

Solid electrolytes with oxygen ion conductivity used as potentiometric or amperometric electrochemical cells enable partial pressures, activities and concentrations of oxygen to be determined in gases, melts and solids. Interactions between the solid electrolyte and hot aggressive measuring media require adaptation of the ceramic materials to the actual operating conditions. Results of experimental investigations on oxygen activities in melts of metals, glasses and salts by potentiometric measurements are presented. Solid electrolyte cells with a current flow are developed to investigate oxygen stoichiometry and thermodynamic properties of solid oxides. Coulometric and polarographic modes of solid electrolyte cells are presented. Investigations on nuclear fuels, oxide semiconductors and ceramic superconductors demonstrate the efficiency of the method.