ZrO2–Sc2O3 Solid Electrolytes Doped with Yb2O3 or Y2O3

Russian Journal of Electrochemistry - The effects of the Y2O3 and Yb2O3 co-doping impurities on the transport characteristics and stabilization of the cubic phase in solid solutions based on...     

Changes in the supermolecular structure and physico-mechanical properties of a polycarbonate subjected to supplementary heat treatment

The possibility of modifying the supermolecular structure of polycarbonate by suitable supplementary heat treatment is demonstrated. An improvement in the physico-mechanical and service properties controlled by the supermolecular structure of the polycarbonate is noted.Departmental Plastics Laboratory, Ministry of the Machine-Tool and Tool Industry of the USSR, Moscow. Moscow Mendeleev Chemical Engineering Institute. State Scientific-Research Institute of Machine Science, Moscow. Translated from Mekhanika Polimerov, Vol. 5, No. 2, pp. 347–349, March–April, 1969.     

Molecular Interactions of L-Histidine in an Aqueous Buffer Solution in the Temperature Range of 288–313 K

Russian Journal of Physical Chemistry A - The behavior of L-histidine (His) in an aqueous buffer solution (pH 7.4) is studied via densimetry and differential scanning calorimetry. The densities and...     

Ceramic membranes based on scandium-stabilized ZrO2 obtained by tape casting technique

Results of studies of solid-electrolyte membranes with the composition of 89 mol % ZrO₂-10 mol % Sc₂O₃-1 mol % CeO₂ obtained using the technique of slip casting on a moving tape are presented. Optimization of technological parameters of membrane casting and sintering allowed manufacturing parallel plane gastight plates with the thickness of 200–250 μm that were tested in model solid oxide fuel cells (SOFC) of planar design with standard electrodes based on nickel-containing cermets and lanthanum-strontium manganite. It is shown that though conductivity of such membranes is lower as compared to that of compacted and sintered compacted samples due to diffusion of the aluminum oxide admixture in the course of the manufacturing process, power density of SOFC is sufficiently high and reaches 430 mW/cm² at 850°C.     

Effect of Heat Treatment on the Thermal Conductivity of Single Crystals of ZrO2-Based Solid Solutions Stabilized with Scandium and Yttrium Oxides

Physics of the Solid State - The effect of heat treatment at 1000°C for 400 h on the thermal conductivity of zirconium dioxide crystals stabilized with scandium oxide...     

Structure and Transport Properties of Zirconia-Based Solid Solution Crystals Co-Doped with Scandium and Cerium Oxides

The crystals of (ZrO₂)_1–x(Sc₂O₃) _x (СeO₂)_0.01 solid solutions (x = 0.08–0.10) were obtained by directional crystallization. The crystals of the grown composites were semitransparent, opalescent, and without cracks and had varying microstructure in the bulk. In the range of compositions under study, it was impossible to obtain optically homogeneous, fully transparent crystals. The crystals grown at a growth rate of 10 mm/h had a nonuniform distribution of ceria along the length of the ingot. The introduction of ceria in an amount of 1 mol % increased the conductivity of the crystals, but the increase in the specific electric conductivity depended on the Sc₂O₃ content and the phase composition of the crystals. The highest conductivity was inherent in the (ZrO₂)_0.89(Sc₂O₃)_0.10(CeO₂)_0.01 crystals.     

Analysis of electric properties of ZrO2-Y2O3 single crystals using teraherz IR and impedance spectroscopy techniques

The data obtained by impedance spectroscopy (1 Hz to 32 MHz) and broad-band dielectric spectroscopy (30 GHz-150 THz) are presented for crystals based on zirconia doped by 1.5–30 mol % Y₂O₃ or 10 mol % Sc₂O₃ and 1 mol % Y₂O₃. The maximum of ionic conductivity is confirmed for the latter composition in the working temperature range of solid oxide fuel cells where the doping by scandium and yttrium oxides makes it possible to obtain isotropic single crystals. Dependences of dielectric permeability and high-frequency conductivity of materials on the composition of crystals and temperature are presented.     

Ionic conductivity,phase composition,and local defect structure of ZrO2-Gd2O3system solid solution crystals

Journal of Solid State Electrochemistry - The crystalline structure, ionic conductivity, and local structure of ZrO2-Gd2O3solid solution crystals have been studied for a wide range of compositions....     

Thermal Conductivity of Cubic ZrO2 Single Crystals Stabilized with Yttrium Oxide

Physics of the Solid State - The temperature dependence of the thermal conductivity of cubic ZrO2 single crystals stabilized with yttrium oxide from 8 to 40 mol % has been studied in the...