We report the synthesis of high quality epitaxial bilayers of LaMnO3/LaCoO3 (LCO/LMO) on (001) LaAlO3, by spin-coating of a polymeric aqueous solutions. The bilayer shows a very large increase of the magnetization coercive field (approximate to 3000%) with respect to the isolated LMO or LCO films. We suggest that the origin of this effect is a strong Mn4+-O-Co2+ exchange interaction at the interface. Our results demonstrate that a simple chemical method is able to produce high quality epitaxial heterostructures in which interfacial effects can modify substantially the properties of the individual layers. (C) 2013 Elsevier B. V. All rights reserved.