Self-Assembled Nanostructures as Templates for the Integration of Nanoparticles in Oxide Surfaces

Abstract

Under properly selected growth conditions, complex oxide thin films might exhibit a tendency towards selforganization allowing obtaining regular arrays of three-dimensional nanostructures. This behavior, together with their rich physics, offers enormous potential for the implementation of new nanodevices. Among complex oxides, manganese perovskites exhibiting colossal magnetoresistance and half-metallic character have emerged as promising candidates for the implementation of new spintronic devices. Manganite thin films are often elastically strained, due to film-substrate lattice mismatch, and this lattice strain can, in some cases, select preferential growth modes leading to the appearance of different self-organized nanostructured morphologies. It is shown that under properly chosen growth conditions long range ordered arrays of nanoobjects, running along the steps direction defined by the miscut angle of the underlying substrate, can be obtained in highly epitaxial La2/3Sr 1/3MnO3 (LSMO) thin films. These results suggest that self-organization process is directly guided by the topological features of the underlying substrate and highlight the relevance of growth kinetic effects. The use of those nanoobjects arrays as nanostencils for fabricating arrays of nanoparticles is also explored.