1994 Fiscal Year Final Research Report Summary
Oxygen Evolution and Uptake Properties of Functional Oxides and The Influence of Hydrogen Dissolved in Them
Project/Area Number |
05650729
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
Metal making engineering
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Research Institution | Osaka University |
Principal Investigator |
YAO Shinya Osaka University, Dept.of Engineering, Associate Professor, 工学部, 助教授 (90029299)
|
Project Period (FY) |
1993 – 1994
|
Keywords | ITO, / Transparent Electrode / Hydrogen Dissolution / Water Vapor Dissolution / C-Rare-earth Related Structure / Oxygen Evolution / Rare-earth Oxide / Electrical Conductivity |
Research Abstract |
The evolution and uptake of oxygen in ITO (In_2O_3+SnO_2) powders were investigated utilizing a closed-system oxygen analyzer with high sensitivity. P (O_2) -C (O) -T curve for P (O_2) =10^<-4>atm was determined ; however, it depend on heating-cooling history. A precipitation coud not be observed by Powder XRD analysis, and therefore we may conclude that the interfacial energy of domain interface has an important role on the evolution and uptake of oxygen thermodynamicaly. We conducted a similar experiment with ITO sample which had been kept in air and therefore supposed to involve moisture or hydrogen. The P (O_2) -C (O) -T curve obtained was not changed, and the amount of hydrogen involved in ITO could be negligible. Nevertheless, it has been reported that the role of water-vapor in ITO is important. Thus, we examined the dissolution of H_2 and H_2O in Sc_2O_3-HfO_2 compounds and La_2Zr_2O_7, which have similar structures to ITO.For La_2Zr_2O_7 doped with In_2O_3, a distinct dissolution of H_2O was observed ; the H_2O dissolved in ITO is still needed to investigate. We also measured the electrical conductivity sigma of ITO tobether with the measuremetns of oxygen evolution. Change in sigma corresponds to the oxygen evolution and also desorption of probably CO gas absorped. The surface conduction of ITO should be examined in terms of oxygen evolution.
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Research Products
(4 results)