In this work lanthanum strontium cobalt ferrite (La0 6Sr0 4Co0 2Fe0 O-8(3-delta)) films deposited by spray-pyrolysis onto commercial yttria stabilized zirconia substrates were investigated by photothermal spectroscopy It is shown that by using the thermal-electrical analogy model It is possible to obtain the thermal properties of two-layer composite systems simultaneously without the need to spread them and thus to evaluate the thermal mismatch between the substrate and the deposited film The thermal diffusivity of the 8YSZ substrate was found to be 6 6 x 10(-3) cm(2)s(-1) whereas for the La0 6Sr0 4Co0 2Fe0 8O3-delta films it ranged between 047 and 9 26 x 10(-4) cm(2)s(-1) We have found that for film thickness beyond 3 06 pm the thermal expansion coefficient becomes relevant indicating that the optimum film deposition time lies between 10 and 20 min (C) 2010 Elsevier B V All rights reserved