Authors: K Rodrigo S Heiroth M Lundberg N Bonanos K Mohan Kant N Pryds L Theil Kuhn V Esposito S Linderoth J Schou T Lippert
Publish Date: 2010/08/31
Volume: 101, Issue: 4, Pages: 601-607
Abstract
Electrical characterization of 10 mol gadolinia doped ceria CGO10 films of different thicknesses prepared on MgO100 substrates by pulsed laser deposition is presented Dense polycrystalline and textured films characterized by fine grains grain sizes 18 nm and 64 nm for a 20nm and a 435nm film respectively are obtained in the deposition process Grain growth is observed under thermal cycling between 300 and 800°C as indicated by Xraybased grainsize analysis However the conductivity is insensitive to this microstructural evolution but is found to be dependent on the sample thickness The conductivity of the nanocrystalline films is lower 70×10−4 S/cm for the 20nm film and 36×10−3 S/cm for the 435nm film both at 500°C than that of microcrystalline bulk samples 6times 103 S/cm at 500°C The activation energy for the conduction is found to be 083 eV for the bulk material while values of 106 and 080 eV are obtained for the 20nm film and the 435nm film respectively The study shows that the ionic conductivity prevails in a broad range of oxygen partial pressures for example down to about 10 −26 atm at 500°C
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