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We investigated by Raman spectroscopy (RS) the crystalline quality of CeO 2 thin films radio frequency magnetron sputtered on n-type (111) Si substrates from CeO 2 target. The deposition temperature was in the range of 200-800 • C. We also realized structural investigations on CeO 2 layers after Rapid Thermal Annealing (RTA) performed in the range of 750-1000 • C for 30 s under nitrogen atmosphere. So this study displays that a high-growth temperature and a high post-growth-RTA temperature improves the crystalline structure of the film.In fact, the best crystalline quality, which is close to the CeO 2 target taken as a reference, is obtained for a CeO 2 layer deposited at 800 • C and post-annealed at 1000 • C for 30 s.

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A multiscale numerical model is developed to predict the thermal radiative properties (TRP) of rough La2NiO4+δ coatings. The model integrates intrinsic and extrinsic contributions related to the chemical composition and the texture, respectively. High-temperature infrared reflectivity and thermogravimetric measurements on a La2NiO4+δ single crystal make it possible to understand the role of the excess oxygen in the intrinsic TRP. We show that dense ceramics with thicknesses higher than 4 μm are optically thick, and that one can adjust the surface roughness parameters to predict their TRP.

Thermal radiation is likely to play an important role in the calculation of the energy balance in solid oxide fuel cells (SOFCs), due to their high operating temperatures (6001-10001C). However, the majority of previous studies dealing with this issue have used room-temperature radiative data for determining the overall heat transfer process within a given cell, which could lead to an inexact appreciation of the role played by the thermal radiation. Consequently, the thermal field within the cell could also be incorrectly determined; however, accurate knowledge of the thermal field is important in order to understand the mechanical behavior of SOFCs. Several parameters, including chemical composition, texture, thickness, and of course operating temperature, have a large effect on the radiative properties of a given compound. As a first step to elucidate the temperaturedependent behavior of SOFCs, we deposited an La 2 NiO 41d cathodic layer on a planar ZrO 2 -8% Y 2 O 3 electrolyte-supported SOFC and investigated its radiative properties using hightemperature infrared emissivity spectroscopy (1001-9001C). Additional X-ray diffraction, thermo-gravimetric analysis, and environmental scanning electron microscopy measurements were also made to study the role played by both the chemical composition and texture on the radiative properties of the cell. 30 J. Stevenson-contributing editor *Member, The American Ceramic Society.

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