Defect Structure Of Mg‐Doped LaCrO3 Model And Thermogravimetric Measurements

Chemical stability and cation stoichiometry determine the applicability of LaCrO3 as a high‐temperature oxide electrode. A model for the behavior of acceptor‐doped LaCrO3, as a function of oxygen activity is proposed. The model is in agreement with experimental data on Mg‐doped LaCrO3. Stability regimes and compensation mechanisms at various oxygen activities and temperature are presented. Copyright © 1984, Wiley Blackwell. All rights reserve

High-temperature Redox Behavior Of Doped SrTiO3 And LaCrO3

The stability of high-temperature fuel cell electrodes to their ambient environment is important for the long-term reliability of fuel cells. In this report the behavior of oxide electrode materials as a function of oxygen activity and temperature is considered. Models for the oxidation-reduction behavior of both p- and n-type oxides are presented. These models take into account the absorption and evolution of oxygen which take place as oxygen activity is varied. The resulting instability in electrical conductivity is explained as a consequence of changes in carrier concentration due to variability in ionic defect concentration. The proposed models are applied to acceptor-doped LaCrO3 and donor-doped SrTiO3. It is shown that the models explain the experimental data well and as a consequence diagram can be made which show the regions of oxygen activity and temperature for which stability of electrical conductivity and defect structure might be expected. © 1985

Oxygen Activity Dependence Of The Defect Structure Of La-doped BaTiO3

A model for the behavior of donor doped BaTiO3 as a function of oxygen activity is proposed. Thermogravimetric measurements show good agreement with the proposed model. The results show that donor-doped BaTiO3 is stoichiometric with electronic compensation of the donor at low oxygen activity, but with increasing oxygen activity, compensation becomes ionic as excess oxygen is absorbed. The possible compensation mechanisms are discussed. © 1984 Chapman and Hall Ltd

Oxidation-reduction Behaviour Of La-doped SrTiO3

Thermogravimetric measurements as a function of oxygen activity were performed in the temperature range of 1200 to 1400° C on a series of lanthanum SrTiO3 compounds. A model which assumes the absorption of excess oxygen in the structure which compensates the donors by formation of cationic defects is postulated. Comparison of this model with the experimental results show reasonable agreement. © 1984 Chapman and Hall Ltd

Processing method for superconducting ceramics

A process for preparing a superconducting ceramic and particularly YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}, where {delta} is in the order of about 0.1--0.4, is carried out using a polymeric binder which decomposes below its ignition point to reduce carbon residue between the grains of the sintered ceramic and a nonhydroxylic organic solvent to limit the problems with water or certain alcohols on the ceramic composition