Inhomogeneous magnetic state induced by stress effect in epitaxial La0.67Sr0.33MnO3 films

Abstract

La0.67Sr0.33MnO3 thin films with different thicknesses have been grown on [001] LaAlO3 substrates to investigate the structural, transport and magnetic variation induced by film thickness and lattice misfit. The x-ray diffraction results show the in-built stress evolution from a fully strained layer (∼10 nm thickness) to a completely relaxed layer (∼150 nm thickness), which can be well explained by the stress effect. Distinct transport and magnetic behaviors are observed, which depends strongly on film thickness. In particular, magnetization measurements show a non-uniform magnetic state in the strained film that we attribute to phase-separated clusters with ferromagnetic and antiferromagnetic domains induced by the epitaxial strain due to the lattice mismatch.