A. V. Kuz’min

Electrical conductivity of CaZr1 − x (x = 0.01–0.20) in dry and humid air

The total conductivity of CaZr1 − xScxO3 − α (x = 0.01–0.20) materials has been measured by the four-probe dc method at temperatures from 600 to 900°C in humid air (pH2O = 40–2500 Pa), and CaZr0.95Sc0.05O3 − α has been characterized by impedance measurements. The ion and proton transport numbers in CaZr0.95Sc0.05O3 − α have been determined as functions of air humidity. The observed anomalies in the temperature dependences of electrical conductivity for the materials studied have been compared to dilatometry data and interpreted in terms of structural changes in their oxygen sublattice.

Phase composition and conductivity of La1 − xSrxScO3 − α (x = 0.01−0.20) under oxidative conditions

The phase composition was studied and overall conductivity of oxides La1 − xSrxScO3 − α (x = 0.01−0.20) was measured as dependent on air humidity (pH2O = 0.04−2.35 kPa) in the temperature range from 100 to 900°C. The samples were synthesized in air at 1600°C. They are single-phase, with a perovskitetype structure with orthorhombic distortions and the density of 94–99%. The conductivity measurements were carried out using the impedance technique and four-probe dc technique. The contributions of bulk and grain boundary resistances were determined, effective conductivity activation energies were calculated.

Total and hole conductivity in the BaZr1 − xYxO3 − α system (x = 0.02−0.20) in oxidizing atmosphere

The total and hole (p-type) conductivities are measured in the BaZr1 − xYxO3 − α system (x = 0.02−0.20) in the temperature range of 600–900°C as a function of air humidity (pH2O = 0.04−3.17 kPa). The model of defect formation in BaZr1 − xYxO3 − α oxides in the presence of water vapor is discussed and the literature data are analyzed.

Effect of scandium sublattice defectiveness on ion and hole transfer in LaScO3-based proton-conducting oxides

The effect of Sc-sublattice defectiveness, at the acceptor doping or making it deficient in cations, on hydrogen content in and electrophysical properties of La0.9Sr0.1ScO3 is studied.

Hydrogen content in proton-conducting perovskites CaZr1 − xScxO3 − x/2 (x = 0.0–0.2)

The hydrogen content in CaZr1 − xScxO3 − x/2 (x = 0.00–0.20) and BaZr0.9Y0.1O3-α (for comparison) was studied by powder nuclear microanalysis. The samples were saturated with heavy water (D2O) vapors at 350 and 400°C in air. The chemical expansion of the CaZr0.95Sc0.05O3-α and BaZr0.95Y0.05O3-α samples at 700°C was measured at different water vapor pressures. A model was suggested to explain the lowered hydrogen content in oxides based on CaZrO3.

Partial conductivities in perovskites CaZr1–xScxO3–α (x = 0.03–0.20) in an oxidation atmosphere

Partial (ionic, proton, and hole) conductivities of oxides CaZr1–xScxO3–α(x = 0.03–0.20) with the perovskite structure in air atmosphere have been studied as functions of temperature in the range of 600–900°C and partial water-vapor pressure in the range of

Electrode materials for solid oxide fuel cells with proton-conducting electrolyte based on CaZrO3

{P_{{H_2}O}}

Electrical conduction nature and phase transition in CaTi1−xFexO3−δ (x = 0.1–0.5)

= 40–2500 Pa. The influence of the humidity of the atmosphere on the relative change in the concentration of oxygen vacancies as a function of temperature has been estimated.