Long-range spontaneous structural ordering in barium stannate thin films.

We have studied spontaneous structural ordering in epitaxial barium stannate thin films, grown on SrTiO₃(001) substrates by pulsed laser deposition. X-ray diffraction analysis revealed satellite reflections around the Bragg peaks, indicative of nanoscale periodic ordering in the out-of-plane direction. We find that mass transport strongly affects this spontaneous ordering, and that the thin film growth rate can be used to tune the periodicity of the superlattices, here between 4.3 and 57.7 nm. [ABSTRACT FROM AUTHOR]