Electroconductivity, Nature of Conduction, Thermodynamic Stability of the BaPr1 –xYxO3 – αCeramics

Abstract

The electroconductivity and the nature of conduction of vacuum-dense ceramics BaPr_{1 – x} Y _x O_{3 – α}(x= 0.05–0.15) is studied at temperatures of 373 to 985°C, $P_{0_2}$ of 2.1 × 10⁴to 10^–11Pa, and $P_{{\text{H}}_2 0}$ of 40 to 2400 Pa. The coefficient of linear thermal expansion is measured. The ceramics have a perovskite structure and are practically p-type semiconductors with a maximum conductivity of 0.26 S cm^–1at x= 0.10 and 800°C, in air. The share of ionic (proton) conductivity of the ceramics does not exceed 0.2–0.4%. The conductivity is weakly dependent on the air humidity. In a hydrogen-containing atmosphere, the ceramics undergoes reduction with destruction. Boundaries of thermodynamic stability of BaPr_0.9Y_0.1O_{3 – α}at 500–900°C are determined.