Shape of platinum nanoparticles supported on SrTiO3:: Experiment and theory

Platinum nanocrystals of about 30-100 nm size were grown on SrTiO3 substrates in different orientations. Their shapes were investigated using first-principles methods and compared to scanning electron microscope images. Analysis of the results for several different surface orientations shows epitaxial growths, uniform size distributions in regular arrays, partial wetting, and several different shapes. In particular, we observe a bimodal distribution of particle shapes, distinguished by the relative size of the (100) facets. This observation is explained by the changes in the surface energy caused by the surface reconstruction.