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Your search keyword '"Buscaglia, A."' showing total 63 results
Start Over Author "Buscaglia, A." Publisher elsevier ltd
63 results on '"Buscaglia, A."'

49. Oxygen transport and chemical compatibility with electrode materials in scheelite-type LaWxNb1−xO4+x/2ceramic electrolyte

Author

Canu, G, Buscaglia, V, Ferrara, C, Mustarelli, P, Gonçalves Patrício, S, Batista Rondão, A, Tealdi, C, Marques, F, FERRARA, CHIARA, Batista Rondão, AI, Marques, FMB, Canu, G, Buscaglia, V, Ferrara, C, Mustarelli, P, Gonçalves Patrício, S, Batista Rondão, A, Tealdi, C, Marques, F, FERRARA, CHIARA, Batista Rondão, AI, and Marques, FMB

Abstract

LaWxNb1−xO4+x/2ceramics (x = 0.16) were prepared via a solid state route and studied with respect to phase stability and mixed ionic and electronic conductivity under conditions of technological relevance for fuel cell applications. The chemical compatibility against standard cathode materials revealed that Sr-doped LaMnO3could be used without detectable chemical interaction up to at least 1000 °C. Impedance spectroscopy measurements performed in the range 400–850 °C, using different atmospheres (air and N2+H2, both dry and water vapour saturated), suggest oxygen transport numbers equal to 1 under oxidising conditions, and decreasing when exposed to extreme reducing conditions. The total conductivity at 800 °C increases from 1.4·10−3 S cm−1in air to 2.5·10−3 S cm−1in wet hydrogen and 6.1·10−3 S cm−1in dry hydrogen, but the observed onset of n-type conductivity has little practical impact under typical fuel cell operating conditions.

Published
2017

50. Microstructure and thermal expansion of Al2TiO5-MgTi2O5 solid solutions obtained by reaction sintering

Author

Giordano, L, Viviani, M, Bottino, C, Buscaglia, M, Buscaglia, V, Nanni, P, GIORDANO, LIVIA, Buscaglia, MT, Nanni, P., Giordano, L, Viviani, M, Bottino, C, Buscaglia, M, Buscaglia, V, Nanni, P, GIORDANO, LIVIA, Buscaglia, MT, and Nanni, P.

Abstract

Solid solutions Mg0.1Al1.8Ti1.1O5 and Mg0.5AlTi1.5O5 were obtained by reaction sintering of mixtures of the binary oxides at 1350-1600 degreesC using different precursor powders. For the composition Mg0.1Al1.8Ti1.1O5, ceramics sintered at 1400-1500 degreesC have high relative density (greater than or equal to 90%), reduced grain size (2-6 mum), low thermal expansion (-0.8 to 0.3 x 10(-6) K-1 in the range 200-1000 degreesC) and reproducible expansion behaviour. At higher temperature, grain size rapidly increases owing to anisotropic and exaggerated grain growth (EGG) resulting in severe microcracking. Microstructure evolution is affected by the nature of the starting oxides, in particular for what concerns the onset temperature of EGG, the size and the fraction of abnormal grains. For the composition Mg0.5AlTi1.5O5, EGG already takes place at 1350 degreesC and materials with grain size < 5 mum are difficult to obtain by conventional reaction sintering. Large grained samples (> 10 mum) of both compositions show a reduced hysteresis and complex thermal expansion behaviour. In particular, heating to 1000 degreesC results in a significant increase in specimen size on return to room temperature. Repeated thermal cycling leads to an increase of the hysteresis. (C) 2002 Elsevier Science Ltd. All rights reserved.

Published
2002

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