Growth of epitaxial strontium barium niobate thin films by pulsed laser deposition

Abstract

We report the growth of epitaxial SrxBa1−xNb2O6 (SBN) thin films by pulsed laser deposition. The films were grown on (100) MgO substrates with thicknesses in the range 200–400 nm. Rutherford backscattering analysis showed that the films have stoichiometric composition identical to the target material. X-ray diffraction 2θ scans indicate single crystalline layers with the (001) orientation perpendicular to the substrate plane. Phi scans on the (221) plane, however, reveal that the films have two in-plane orientations. The unit cell of SBN is rotated in the plane of the film by ±18.4° with respect to the MgO substrate unit cell. This rotation is explained using a model which takes into account both the lattice match and the electrostatic energy within the heteroepitaxial interface.