TY - JOUR
T1 - Directionally solidified CeO2 (or GDC)/CoO eutectic ceramics as cermet precursors for SOFCs anodes
T2 - Microstructure cross-over
AU - Ortega-San-Martin, Luis
AU - Peña, José Ignacio
AU - Larrea, Ángel
AU - Orera, Victor M.
PY - 2011/6
Y1 - 2011/6
N2 - Rods of CeO2 and gadolinium-doped CeO2 (GDC)-CoO eutectics were prepared by directional solidification using a laser heated floating zone (LFZ) technique. The microstructure has been studied as a function of the growth rate from V=10 to 750mm/h. Regular eutectic microstructures are obtained except for the highest growth rate. The interspacing follows the λ2V=C law with C=4.1(3)×10-17 and 2.6(3)×10-17m3/s for CeO2-CoO and GDC-CoO eutectics, respectively. A cross-over between fibrous and lamellar eutectic microstructures was observed depending on the growth rate. The crystallography of the eutectics was studied by Electron Backscatter Diffraction (EBSD). The growth directions [110]GDC∼//[110]CoO, and the interfacial planes (200)GDC//(111)CoO, were identified. Solubility of Co in the ceria matrix was determined by Energy Dispersive X-ray (EDX) Spectroscopy after Co was leached out from the matrix. Co solubility in ceria at 1650°C was found to be less than 1mol%.
AB - Rods of CeO2 and gadolinium-doped CeO2 (GDC)-CoO eutectics were prepared by directional solidification using a laser heated floating zone (LFZ) technique. The microstructure has been studied as a function of the growth rate from V=10 to 750mm/h. Regular eutectic microstructures are obtained except for the highest growth rate. The interspacing follows the λ2V=C law with C=4.1(3)×10-17 and 2.6(3)×10-17m3/s for CeO2-CoO and GDC-CoO eutectics, respectively. A cross-over between fibrous and lamellar eutectic microstructures was observed depending on the growth rate. The crystallography of the eutectics was studied by Electron Backscatter Diffraction (EBSD). The growth directions [110]GDC∼//[110]CoO, and the interfacial planes (200)GDC//(111)CoO, were identified. Solubility of Co in the ceria matrix was determined by Energy Dispersive X-ray (EDX) Spectroscopy after Co was leached out from the matrix. Co solubility in ceria at 1650°C was found to be less than 1mol%.
KW - B. Composites
KW - B. Microstructure-final
KW - D. CeO
KW - E. Fuel cells
KW - Eutectics
UR - http://www.scopus.com/inward/record.url?scp=79953309884&partnerID=8YFLogxK
U2 - 10.1016/j.jeurceramsoc.2010.06.012
DO - 10.1016/j.jeurceramsoc.2010.06.012
M3 - Article
AN - SCOPUS:79953309884
SN - 0955-2219
VL - 31
SP - 1269
EP - 1276
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
IS - 7
ER -