Tailored texture of SrxBa1-xNb2O6 thin films by aqueous chemical solution deposition

Tetragonal tungsten bronzes are normally uniaxial ferroelectrics making crystallographic texture pivotal for optimization of electrical properties. SrxBa1-xNb2O6 (SBN), x = 0.4, 0.5 and 0.6, thin films with out-of-plane (001) or in-plane (310) oriented polarization were deposited by aqueous chemical solution deposition on SrTiO3 (STO)(100) substrates. A texture degree of > 90% was achieved for (001) oriented SBN films on SrO terminated STO, while the (310) oriented films on TiO₂ terminated STO possessed a degree of texture > 50%. The films were in compression compared to bulk due to epitaxial strain, thermal strain, and a reduced lattice parameter of the film due to Ti-doping, all related to the substrate used. The Curie temperature of selected (001) oriented films showed the expected decrease with increasing Sr content, and additional decrease attributed to Ti-doping. A piezo response was measured in (001) oriented films by in situ application of an electrical field during X-ray diffraction measurements.