Détermination de la semi-conduction électronique dans l’oxyde binaire zircone-oxyde de cérium

Millet, Jacques; Guillou, M. Le

doi:10.1051/jcp/1967641726

Cited by 6 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The observed change in dependence on oxygen partial pressure at 1400 K for 'Ce'2Zr207 shown in figure 5 can therefore be understood if the ratio Ce3+/Ce4+ is about unity at 1400 K, greater than unity above 1400 K, and less than unity below 1400 K. The rapid change in resistivity for the higher oxygen partial pressures in the region of 1400 K signifies that the ratio Ce3+/Ce4+ is varying rapidly. This compares closely with the results of Millet and Guillou (1967) for (ZrOz)o.75(Ce02)0.25, in which the ionic transport number halves between 1200 and 1600 K for oxygen partial pressures in the range 1 to 10-3 bar, indicating a large increase in the Ce3+ concentration. It is worth noting that to reduce cerium oxide itself, much lower oxygen partial pressures are needed-at 1442 K Ce3+/Ce4+ is unity in cerium oxide at lO-5I bar (Bevan and Kordis 1964).…”

Section: Cerium Zirconate and Stannatesupporting

confidence: 89%

See 1 more Smart Citation

Some properties of zirconates and stannates with the pyrochlore structure

Chapman

Meadowcroft

Walkden

1970

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

The properties of the stannates and zirconates (M2Sn2O7 and M2Zr2O7) of yttrium, lanthanum, cerium and neodymium are discussed, and the materials are considered for possible application in magnetohydrodynamic (MHD) power generation. Measurements are discussed of their structural properties, thermal expansion, thermal diffusivity, electrical resistivity, resistance to oxidation, to chemical corrosion, and to electrolytic corrosion. Thermal shock resistance is also qualitatively assessed. For non-electrical applications, lanthanum stannate has shown the most promise, especially in the corrosion tests. All the materials are insulators below 1000 K, except cerium zirconate which has ample electrical conductivity (> 10 Ω−1 m−1 above 1400 K) for use as an MHD electrode. Cerium zirconate has complicated structural and electrical properties, and must be prepared in low oxygen partial pressures. However, it is easily oxidized and may disintegrate. The equimolar ceria-zirconia solid solution formed when the oxides are fired in air would be more useful as an MHD material.

show abstract

Section: Cerium Zirconate and Stannatesupporting

confidence: 89%

“…These results agree reasonably well with the mean value of 11.8 x 10-6 K -~ for (CeO2)0.25(ZrO2)0. 'i5 between 300 and 1700 K reported by Millet and Guillou (1967).…”

Section: Thermophysical Propertiesmentioning

confidence: 87%

Some properties of zirconates and stannates with the pyrochlore structure

Chapman

Meadowcroft

Walkden

1970

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…In the actual system, nonmobile or less mobile species Vo' and Vo x are formed by the trapping at Vo" of electrons formed by the polarization process. The centers are visible as color centers (8,9). The trapping tends to reduce the electronic current until a stationary state has been reached in which just as many electrons are trapped at Vo" as are released from Vo' and Vo X.…”

Section: Possible Electrode Mechanismsmentioning

confidence: 99%

Platinum Electrodes and Calcia-Stabilized Zirconia

Brook

Pelzmann

Kröger³

1971

J. Electrochem. Soc.

View full text Add to dashboard Cite

Measurements of the direct current-voltage characteristics of calcia-stabilized zirconia using platinum electrodes of various types have been made to investigate possible electrode processes. Depending on the form of the electrode, the rate-limiting step in the electrical conduction sequence can be (a) ionic conduction by O = in the zirconia, (b) electronic conduction in the zirconia, (c) oxygen atom diffusion through the platinum cathode, (d) the transfer of oxygen from the gas phase into the zirconia at the zirconia-gas interface on the cathode side. The conditions, under which each of these situations exists, are explained in terms of the structure of the electrode.Earlier studies on cells Pt, 02[0.85 ZrO2 9 0.15 CaOIPt, 02 with platinum point electrodes (1), or porous platinum electrodes (2), showed the I-V characteristic to be markedly nonohmic. The rate-controlling step responsible for this behavior was found to be confined to the cathode. Two mechanisms of electrode operation appeared to be important (2). At low voltages (e.g., * Electrochemical Society Active Member.

show abstract

The electrical resistivity of some castable zirconias

Meadowcroft

1969

J Mater Sci

View full text Add to dashboard Cite

Détermination de la semi-conduction électronique dans l’oxyde binaire zircone-oxyde de cérium

Cited by 6 publications

References 0 publications

Some properties of zirconates and stannates with the pyrochlore structure

Some properties of zirconates and stannates with the pyrochlore structure

Platinum Electrodes and Calcia-Stabilized Zirconia

The electrical resistivity of some castable zirconias

Contact Info

Product

Resources

About