Structural, magnetic and transport properties of fully epitaxial LaMnO3/LaAlO3 multilayers

Abstract

The structural, magnetic and transport properties of LaMnO3/LaAlO3 (2 unit cells) (LMO/LAO) multilayers with different thicknesses of LMO layer grown on SrTiO3 substrates were studied. Structural investigations confirmed that all the samples were fully epitaxial and the out-of-plane lattice constant increased with rising LMO layer thickness t from 1 to 4 unit cells. Ferromagnetic behavior could be observed only when t was above 2 unit cells, while the coercive field reduced with increasing t. Transport measurements indicated that all the multilayers were insulating and the activation energy of the multilayers were much larger than single-layered LMO films. These results provide a promising route for tuning the structure, electronic and magnetic properties in other strong-correlated materials.