Influence of the Substrate Surface on the Self-Assembly of Ferroelectric PbTiO₃Nanostructures Obtained by Microemulsion Assisted Chemical Solution Deposition

Abstract

The achievement of long range periodicity of ferroelectric nanostructures on substrates remains as a challenge in the processing of devices by the relatively inexpensive selfassembly methods. To this aim, here we make the proposal of processing strategies involving commercial single-crystal SrTiO 3 (100) substrate surface treatment. The topography, global ordering and crystal symmetry of the surface of the treated substrates as well as the near surface layer composition were analysed by Scanning Force Microscopy, Low Energy Electron Diffraction and Auger Electron Spectroscopy, respectively. The study shows that a combination of chemical etching and thermal annealing in air produces smooth and well terraced surfaces which have steps of few unit cells height and a nearly complete TiO 2 termination, , while keeping the 1x1 bulk structure. Preliminary results shows that PbTiO 3 nanostructures, obtained by a novel microemulsion assisted Chemical Solution Deposition method onto such substrates, grow at regular distances and preferentially located at the edges of the substrate surface terraces. Thus, long range order of these nanostructures is envisaged when deposited onto substrates that are treated by the procedure here studied.