Interface structure governed by plastic and structural dissimilarity in perovskite La0.7Sr0.3MnO3 nanodots on rock-salt MgO substrates

Abstract

Self-assembled La0.7Sr0.3MnO3 perovskite nanodots have been grown on highly mismatched rock-salt type MgO substrates by chemical solution deposition. The interfacial dislocation structure indicates that the relaxation mechanism is governed by the easy glide of MgO 1/2〈101〉{101} dislocations towards the interface, where they dissociate into misfit-relieving and tilting components. The latter induce a 4-domain tilt pattern superimposed to the main cube-on-cube epitaxial orientation. It is shown that the inheritance of the rotational component of the Burgers vector has detrimental consequences on the interfacial quality, evidencing the impact of structural and plastic dissimilarity on the design of self-assembled nanostructures.