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Cast, coarse-grained Al-Sc alloys are interesting candidates for high temperature, creepresistant applications due to the formation of a high number density of nanometer sized Al 3 Sc precipitates [1]. Upon addition of Yb to Al-Sc alloys, Yb replaces the Sc forming Al 3 (Sc 1-x Yb x) precipitates (L1 2 structure) [2]. The resulting alloys have higher creep resistance due to the larger lattice parameter mismatch between the matrix and precipitate phases as a result of the substitution of Yb for Sc. The precipitates in Al-Sc-Yb alloys form rapidly at 300˚C and the coarsening kinetics are not slowed when compared with binary Al-Sc alloys [3]. Additions of Zr to Al-Sc alloys do, however, retard the coarsening kinetics of the Al 3 (Sc 1-x Zr x) precipitates [4]. In the present study, Zr is added to an Al-Sc-Yb alloy. The compositions of the alloys studied are Al-0.06Sc-0.02Yb-0.02Zr (at.%) and Al-0.06Sc-0.02Yb-0.005Zr (at.%).

Porous LSCF thin film cathodes suitable for application in Micro Solid Oxide Fuel Cells (μ-SOFCs) were fabricated by spray pyrolysis and pulsed laser deposition. During spray pyrolysis a precursor is sprayed onto a heated substrate, where an amorphous metal oxide film is obtained. Porosity forms during a subsequent annealing process depending on the maximum crystallization temperature. It was possible to fabricate these cathodes with a maximum processing temperature of 650{degree sign}C, which is desirable for the processes and materials involved in μ- SOFCs fabrication. The films are thinner than 1 μm with nanometer-sized grains. The cathode performance was evaluated by determing the area specific resistance. The microstructure proofed to have a strong influence on the cathode performance. Smaller grain sizes led to better performance and can be achieved by low annealing temperature. Furthermore, the microstructure achieved by spray pyrolysis led to better results, than the microstructure achieved by pulsed laser deposition.