Interface Magnetic Coupling in Epitaxial Bilayers of La_0.92MnO₃/LaCoO₃ Prepared by Polymer-Assisted Deposition

We report the synthesis of epitaxial bilayers of ultrathin La 0.92 MnO 3 /LaCoO 3 (LMO/LCO) on SrTiO 3 (STO) by polymer solution deposition. We have achieved an excellent control over the thickness (from ∼4 to ∼20 nm) and roughness of the films, which allows the fabrication of the sharp interfaces required for their functionality. We suggest that the large increase in the coercive field observed in the bilayer with respect to isolated films of LMO or LCO is due to a strong ferromagnetic Mn–O–Co superexchange interaction at the interface. Our results demonstrate that abrupt interfaces can be obtained in epitaxial multilayers by a simple and affordable chemical deposition technique, with the quality required for fundamental studies or highly demanding applications.