Crystalline lanthanum strontium cobalt ferrite (LSCF) was obtained by calcination at a low temperature of 500 degrees C from precursor nanoparticles. The precursor nanoparticles were synthesized by the citrate complex method adding oleic acid as a surfactant, and dynamic laser scattering measurements suggested that they exhibited high dispersibility in the solution with an average diameter less than around 20 nm. The crystallite size decreased and the total specific area increased as the calcination temperature was decreased from 800 to 500 degrees C. It was found that the oleic acid functioned as a surfactant to form homogeneous fine precursor, and then assisted in the crystallization of LSCF even at a low calcination temperature of 500 degrees C. Such a low temperature synthesis suppressed the agglomeration and growth of LSCF particles so that fine powders with particle size less than 20 nm were obtained. (C) 2015 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.