Modification of Oxygen/(Ba0.5Sr0.5)(Co0.8Fe0.2)O3-δ Interfaces Derived by Metal-Organic Deposition. (13th April 2015) - Asano, Koichi
Abstract : In this study, nanoscaled (Ba0.5 Sr0.5 )(Co0.8 Fe0.2 )O3-δ (BSCF) thin films (with thicknesses below 100 nm) have been successfully deposited onto NdGaO3 single crystal substrates using a metal-organic deposition (MOD) method. In contrast to physical vapor deposition techniques, e.g. pulsed-laser deposition or magnetron sputtering, BSCF thin films formed by an MOD method provide the possibility to custom-tailor the surface morphology by subsequent annealing treatments. Changes of surface area or phase composition (cubic, hexagonal BSCF, others) are expected to affect the catalytic activity of oxygen-transport membranes. A study of surface morphologies achieved by a variation of the post-deposition thermal treatment is presented. The electrical properties of selected MOD thin films were determined and compared to data for epitaxial BSCF thin films and bulk samples. Lastly, oxygen exchange kinetics were investigated by electrical conductivity relaxation measurements analyzed in the frequency domain, yielding oxygen surface exchange coefficients k δ ( T ).