Volume 3 • Issue 1 • 1000112 J Nanomedine Biotherapeutic Discov ISSN:2155-983X JNBD an open access journal Research Article Open Access Nanomedicine & Biotherapeutic Discovery Konstantinović et al., J Nanomedine Biotherapeutic Discov 2013, 3:1 http://dx.doi.org/10.4172/2155-983X.1000112 Keywords: Self-assembled nanostructures; Magnetoresistance; Oxide surfaces; Spintronics Introduction e recent idea of using biomolecules with magnetic particles as magnetic markers in living organisms opens the door to a new generation of magnetoresistive detectors with sensitivity over the standard detection by fluorescence [1,2]. is technology is based on the detection of nanometric magnetic labels biologically functionalized by ultra-sensitive magnetic field microsensors due to the change in the resistance. Resistive devices, based on the giant magnetoresistive (GMR) or tunnel magnetoresistive (TMR) effects, have been intensively studied in the emerging field of spintronics [3,4]. Nowadays, magnetic junctions are key components in several commercial products in different areas and recently have been used in new types of test of biomolecular systems with integrated recognition [5-7]. Moreover, a huge increase of tunnelling magnetoresistance has been observed in TMR nanometric junctions based on metallic nanoparticles. Well- defined structures at nanometric scale present an increasing interest due to their unique physical properties allowing envisaging new technological applications. In particular, the large surface to volume ration in nanoparticulate systems holds very promising expectatives in catalysis. A major challenge in nanotechnology is to find a way of positioning nanoelements on surfaces in regular patterns, with nanometric precision yet over large surface areas either by deposition techniques (bottom-up approach) or by lithography plus nanofabrication techniques (top- down approach). Fabrication of artificial nanostructures of oxide materials by top-down approach requires sophisticated technology and has been recognized as a hard-attainable issue. For these reasons, the fabrication of ordered nanostructures, via spontaneous self- organization, is a topic of major relevance. An attractive route is based on using self-assembly properties of basic building blocks to create the patterned nanostructure. In this sense, directed self-organization based on template-assisted processes is a very promising and fast developing research topic in different fields. e tendency of some oxides towards self-organized growth, forming regular arrays of 3D uniform structures, offers enormous potential for the preparation of nanotemplates that can be used for the fabrication of long range ordered nanostructured systems [8]. In this article, we explore the possibility of using long range ordered arrays of nanoobjects, obtained by spontaneous self-assembly in epitaxial La 0.7 Sr 0.3 MnO 3 (LSMO) thin films, as nanostencils for fabricating arrays of metallic nanoparticles (sub-50 nm range) prepared by physical and chemical methods. e preparation of Au nanoparticles arrays by a self- organization process guided by the nanostructured surface morphology of the underlying LSMO is demonstrated to illustrate the suitability of the method. Materials and Methods LSMO thin films were grown on (001)-oriented SrTiO 3 substrates by rf magnetron sputtering from a stoichiometric ceramic target [9]. e crystal structure was characterized by X-ray diffraction (XRD) with Cu Kα radiation. Pole figure has been recorded using a Bruker AXS GADDS system equipped with a 2D X-ray detector. e surface morphology was analyzed by atomic force microscopy (AFM) working *Corresponding author: Konstantinović Z, Institut de Ciència de Materials de Barcelona, CSIC, Campus UAB 08193, Bellaterra, Spain; E-mail: zorica@icmab.es Received June 01, 2013; Accepted June 24, 2013; Published June 27, 2013 Citation: Konstantinović Z, Vodnik V, Saponjic Z, Nedeljkovic J, Pomar A, et al. (2013) Self-Assembled Nanostructures as Templates for the Integration of Nanoparticles in Oxide Surfaces. J Nanomedine Biotherapeutic Discov 3: 112. doi:10.4172/2155-983X.1000112 Copyright: © 2013 Konstantinović Z, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Self-Assembled Nanostructures as Templates for the Integration of Nanoparticles in Oxide Surfaces Konstantinović Z 1 *, Vodnik V 2 , Saponjic Z 2 , Nedeljkovic J 2 , Pomar A 1 , Santiso J 3 , Sandiumenge F 1 , Balcells Ll 1 and Martinéz B 1 1 Institut de Ciència de Materials de Barcelona, CSIC, Campus UAB 08193, Bellaterra, Spain 2 Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, Serbia 3 Centre for Nanoscience and Nanotechnology, (CSIC-ICN) Campus UAB, 08913 Bellaterra, Spain Abstract Under properly selected growth conditions, complex oxide thin films might exhibit a tendency towards self- organization 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 La 2/3 Sr 1/3 MnO 3 (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.