T 44 The types of surface exchange and diffusion of oxygen in La0.7Sr0.3CoO3-delta [Text] / A. N. Ezin, E. K. Kurumchin, I. V. Murygin, V. I. Tsidilkovski, G. K. Vdovin // Solid State Ionics. - 1998. - V. 112, N 1-2. - P117-122. - Bibliogr.: p. 122 (19 ref.) . - ISSN 0167-2738 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ХИМИЯ -- ДИФФУЗИЯ ПОВЕРХНОСТНАЯ -- ПОВЕРХНОСТНАЯ ДИФФУЗИЯ -- РЕАКЦИИ ОБМЕНА -- КИСЛОРОД -- O2 -- La -- Sr -- Co -- ЛАНТАН -- СТРОНЦИЙ -- КОБАЛЬТ -- La0.7Sr0.3CoO3-дельта -- ОБМЕН КИСЛОРОДА -- ДИФФУЗИЯ КИСЛОРОДА Аннотация: The kinetics of the oxygen isotopic exchange between La0.7Sr0.3CoO3-delta and oxygen gas has been studied at on oxygen pressure of 1.28 * 10(3) Pa and temperatures from 786 to 875 degrees C. Experimental time dependencies of molecules (00)-0-16-0-16, (00)-0-18-0-16, (00)-0-18-0-18 content in the gas phase have been analyzed by the method first proposed by the authors. Using this method we have directly calculated both the rates of the different types of surface exchange and the bulk diffusivity of oxygen from experimental data. It has been shown that under the experiment conditions at elevated temperatures the surface exchange proceed by the dissociative adsorption-desorption mechanism |
T 89 Tsidilkovski, V. I. Thermoelectric power of high-temperature proton conducting oxides [Text] / V. I. Tsidilkovski, V. P. Gorelov // Physics and chemistry of novel materials: 4th Bilateral Russian-German Symposium (Febr. 24-March 1, 1999): Progr. and abstr. - 1999. - 3.12 (1 pp.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ПРОВОДНИКИ ПРОТОННЫЕ -- ПРОВОДИМОСТЬ ПРОТОННАЯ -- ОКСИД -- ТЕРМОЭДС -- ФАЗА ГАЗОВАЯ |
T 89 Tsidilkovski, V. I. Thermodynamic isotope effect H/D/T in proton-conducting oxides [Текст] / V. I. Tsidilkovski // Solid State Ionics. - 2003. - Vol. 162-163. - С. 47-53. Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): PROTON CONDUCTING OXIDES -- THERMODYNAMIC -- ISOTOPE EFFECT -- TRITIUM -- HYDROGEN Аннотация: The thermodynamic isotope effect H/D/T for proton conducting oxides in equilibrium with gas phase was theoretically considered. The difference in concentrations n of hydrogen, deuterium and tritium in the same samples exposed to gas phases containing the vapors of only one of these elements was analyzed. The oxides of the AIIB1-xIVRxIIIO3-y type were considered in the frame of some known defect formation models. It was shown that for a characteristic change in the proton-associated vibration frequencies with isotopic substitution of protons, the concentrations nH, nD and nT, under equivalent external conditions, might be appreciably different. The effect essentially depends on the external conditions and on the ratio of nH to dopant concentration x: it is maximal at low nH and disappears when nH/x>1. A possibility of direct experimental observation of the thermodynamic isotope effect in perovskite oxides is briefly discussed.???? \\\\Cserver\\dist\\НБО\\Cтатьи БД ИВТЭ\\Solid State Ionics\\2003, V. 162-163, С. 47-53.pdf |
T 89 Tsidilkovski, V. I. Thermoelectric power of proton conducting oxides [Текст] / V. I. Tsidilkovski, V. P. Gorelov, V. B. Balakireva // Solid State Ionics. - 2003. - Vol. 162-163. - С. 55-61. Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): PROTON CONDUCTING OXIDES -- THERMOELECTRIC POWER Аннотация: A theory of thermopower for proton conducting oxides (PCO) with protons, oxide ions and different electron charge carriers has been developed. The thermopower альфа of SrCe0.95Y0.05O3 дельта, BaCe0.9Nd0.1O3 дельта and of a zirconium–yttrium electrolyte as a reference material was measured in both oxidizing and reducing atmospheres. The analysis of the data obtained for the region of pure protonic conduction of SrCe0.95Y0.05O3 дельта using our theoretical results and including vibrational and configurational contributions to альфа allowed determining both the partial entropy of protons and their heat of transport. The concentrations of protons and their temperature dependences determined from the entropy term agreed well with the experimental data available from hydrogen uptake studies. \\\\Cserver\\dist\\НБО\\Cтатьи БД ИВТЭ\\Solid State Ionics\\2003, V. 162-163, С. 55-61.pdf |