Cation interdiffuison in Gd- and Sm-doped ceria (CeO2)

Contact: Dr.-Ing. Heike Störmer

Due to their high oxygen conductivity the intensely studied Samarium (Sm) and Gadolinium (Gd) dopedCeO2 systems are promising candidates for application as electrolyte material in SOFCs. However, some ofthe basic properties of Sm- and Gd-doped CeO2 are still unknown. For example, cation interdiffusion coefficients of Sm- and Gd-ions in CeO2 were not investigated up to now which were determined in this study at application-relevant temperatures between 970 °C and 1170 °C.

Sm2O3 and Gd2O3 films were deposited on dense, polycrystalline CeO2 substrates by pulsed laser deposition. The samples were annealed at temperatures between 970 °C and 1270 °C for up to 100 h in an oxidizing atmosphere. Analytical and structural characterization was performed by transmission electron microscopy (TEM). Interdiffusion profiles were acquired by energy-dispersive X-ray spectroscopy (EDXS) and electron energy-loss spectroscopy (EELS). Structure determination was performed by comparing Fourier transforms of high-resolution TEM images and selected area electron diffraction patterns with simulated of diffraction patterns.

Publications:

S.J. Litzelman, R.A. De Souza, B. Butz, D. Gerthsen, M. Martin, H.L. Tuller, Heterogeneously doped nanocrystalline ceria films by grain boundary diffusion: Impact on transport properties, Journal of Electroceramics 22, 405 (2009), DOI: 10.1007/s10832-008-9445-y 

C. Rockenhäuser. B. Butz. N. Schichtel, J. Janek, R. Oberacker, M.J. Hoffmann, D. Gerthsen, Microstructure evolution and cation interdiffusion in thin Gd2O3 films on CeO2 substrates, J. Europ. Ceram. Soc. 34, 1235 (2014), http://dx.doi.org/10.1016/j.jeurceramsoc.2013.11.043

C. Rockenhäuser, B. Butz, H. Störmer, D. Gerthsen, Microstructure evolution and cation interdiffusion in thin Sm2O3 films on CeO2 substrates, J. Am. Ceram. Soc., submitted.