Review on Ceramic Interphases by Transmission and Scanning Electron Microscopy

ANALÍA SOLDATI; ALEJANDRA MONTENEGRO-HERNÁNDEZ; BAQUE L.; H.E. TROIANI; LILIANA MOGNI; ANJA SCHREIBER; SERQUIS A.

PRAKTISCHE METALLOGRAPHIE

CARL HANSER VERLAG

Lugar: Berlin, Germany; Año: 2014 p. 675 - 688

0032-678X

The Focused Ion Beam (FIB) technique wasused to prepare site-specific samples frominterfacial regions of different solid oxidefuel cells assemblies. Transmission andScanning Electron Microscopy on the FIBfoils combined with Electrochemical ImpedanceSpectroscopy (EIS) allowed thecharacterization of the electrode/electrolyteinterphases and the determination ofits influence on the cell performance afterlong-term operation conditions. This workreviews two cases: on one hand, Ln2NiO4+d(Ln= La, Nd) cathodes deposited on bothY0.08Zr0.92O1.96 and Ce0.9Gd0.1O1.95 electro-lytes, that react at 900 °C during the adhesiontreatment and at temperatures higherthan 650 °C during the EIS measurements.These samples present a reaction layer of10 nm thickness, which contains elementsof both phases and was found responsibleof the cell performance degradation. Onthe other hand, La0.4Sr0.6Co0.8Fe0.2O3-dcathodes showed excelent performanceon Ceria electrolytes, even after 1 000 h atoperation conditions. In that case, the microscopicanalyses of FIB foils showed asemi-coherent interphase growth.