抄録
The oxygen partial pressure as well as temperature and the composition of oxide are one of the important parameters for studying phase equilibria. Thermodynamic properties of phase boundaries and those of nonstoichiometric oxide are obtained from the phase diagram. The defect structures of nonstoichiometric oxide are discussed from the oxygen partial pressure dependence of the departure from stoichiometric composition and that of the electrical conductivity.
The solid electrolyte and oxide semiconductor oxygen sensors are used for measurement of the oxygen partial pressure. The principle and some problems of measurement, and characteristics of each oxygen sensor are reviewed briefly, and both oxygen sensors are compared each other.
The oxygen partial pressures in the intermediate and low oxygen partial pressure ranges are controlled precisely by pumping oxygen into or from flowing (or circulating) gases such as inert, CO2 and H2 gases with a stabilized zirconia cell.
The application of oxygen sensor and oxygen pump to obtain thermodynamic properties of phase boundaries and nonstoichiometric oxide, and to determine defect structure of nonstoichiometric oxide at constant temperature is described.
