Strain effect on the electrical conductivity of epitaxial La0.67Sr0.33MnO3 thin films

Sr-doped LaMnO3 is the conventional cathode material used in solid oxide fuel cells. In this work, we utilize epitaxial thin films grown on various single-crystal oxide substrates as a model system to systematically vary the amount of strain imposed upon the La0.67Sr0.33MnO3 films. We find that with increasing tetragonal distortion, the activation energy for small polaron hopping increases and the conductivity decreases by as much as an order of magnitude compared to that of the bulk material. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.