N. V. Sharova

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

AbstractThe electroconductivity and the nature of conduction of vacuum-dense ceramics BaPr1 – xYxO3 – α(x= 0.05–0.15) is studied at temperatures of 373 to 985°C,

Electroconductivity and Ion Transport in Protonic Solid Electrolytes BaCe0.85R0.15O3–δ, where R is a Rare-Earth Element

P_{0_2}

Charge Transport in BaCe0.85R0.15O3 − δ (R = Sm, Pr, Tb) in Oxidizing and Reducing Environment

of 2.1 × 104to 10–11Pa, and

Proton-oxygen conductance in substituted perovskites ATi0.95M0.05O3- α (A = Ca, Sr, Ba; M = Sc, Mg) in the reducing hydrogen-containing atmospheres

P_{{\text{H}}_2 0}

Electroconduction and the Nature of Ionic Transport in BaZr0.95Nd0.05O3−δ

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 BaPr0.9Y0.1O3 – αat 500–900°C are determined.

Charge Transport in BaCe 0.85 R 0.15 O 3 - d (R = Sm, Pr, Tb) in Oxidizi

The effect of the cation nonstoichiometry on the electroconduction, electrotransfer, and stability in humid air of solid proton-conducting electrolyte BaxCe0.97Nd0.03O3 - δ (0.90 ≤ x ≤ 1.10) is studied. The electroconduction is found to decrease with decreasing content of BaO (x ≤ 1.0) and weakly depend on the BaO excess (x> 1.0). Ceramics of a stoichiometric composition (x = 1) and with lack of barium is stable when stored in humid air at room temperature, as opposed to the ceramics with barium excess, which rapidly decomposes in these conditions. The conduction of materials under study in oxidizing environment is ion-hole and in reducing media, ionic (proton + oxygen). The cation nonstoichiometry barely affects the nature of the ion transfer. An analysis of possible models for the formation of defects shows oxygen vacancies to be always present in BaxCe0.97Nd0.03O3 - δ, even at the CeO2 excess exceeding the content of neodymium.