Electrochemical Properties of Nitride Phases in the Si3N4–Ca3N2and Si3N4–AlN–Ca3N2Systems

The electrical conductivity of silicon nitride and its solid solutions with calcium nitride and aluminum nitride was measured in the ranges 400–900 and 1000–1300°C. The conduction mechanisms were found to be substantially different in these temperature ranges. The Si3N4–Ca3N2solid solutions exhibited high ionic conductivity between 400 and 900°C. The densest and most oxidation-resistant materials were obtained in the Si3N4–AlN–Ca3N2system (Al introduced as fine powder and then nitrided).