The mechanical stability is an important parameter to gain knowledge in the potential applications of a novel design of electrolyte-supported SOFC, based on yttria-stabilised zirconia (YSZ) and NiO-YSZ composites, with cross-linked channels (∼90 μm of diameter). In this experimental work, the mechanical properties (hardness, H and Young's modulus, E) at different applied loads have been studied using the nanoindentation technique and the equivalent indenter method. On the other hand, the different fracture mechanisms have been determined using atomic force microscopy (AFM), observing the plastic behaviour that takes place during the indentation process. H value for YSZ is higher than that for NiO-YSZ, while E values for YSZ and NiO-YSZ are 260 ± 15 and 205 ± 20 GPa, respectively. Only YSZ samples present several radial cracks at the corners nucleated by sharp indentation, thus indicating that H values have been underestimated.

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