Conference of Monica Burriel - Post-doctoral fellowship from Imperial College, London

New oxide nano-structured materials with tailored properties for IT-SOFCs

With the aim of developing SOFC cathode materials offering low polarization losses and long-term stability at intermediate operating temperatures, my research has focused on understanding the properties of alternative types of MIEC (mixed ionic and electronic conducting) ceramic materials. In my talk I will present some examples of promising novel oxides, mainly from the Ruddlesden-Popper Ln2NiO4+ (Ln = La, Nd, Pr) family and the double perovskite RBaCo2O5+ (R = rare earth) family, focusing on the effect of the structure, orientation and composition of the compounds on the derived properties. I will also introduce the new surface science instrumentation available at Imperial College: a combination of Low Energy Ion Scattering (LEIS) and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), which allows the study of the surface chemistry with unparalleled precision and sensitivity and provides a comprehensive 3D image of the composition, including the interfaces and grain boundaries. Finally, I will show some examples and recent results using this unique combination of techniques for the investigation of the oxygen incorporation and transport in these materials, as well as the factors limiting the oxygen exchange process, including cation segregation and secondary phase formation occurring at high temperatures.