Epitaxial Growth of (Sr, Ba)Nb₂O₆ Thin Films by Pulsed Laser Deposition

Abstract

Thin films of (Sr, Ba)Nb 2 O 6 (SBN) were prepared on SrTiO 3 (100) substrates by a pulsed laser deposition and their crystallographic properties were investigated. Epitaxially grown films with the c -axis perpendicular to the substrate were obtained at substrate temperatures higher than 650°C in an oxygen atmosphere (containing 8% O 3 ) of 3 mTorr. An X-ray phi scan analysis indicates that the films have antiphase domains in the c -plane and the relationship is SBN<100>//SrTiO 3 <310>. The lattice mismatch between the film and the substrate is less than 1%, which contributes to the desirable crystalline quality of SBN films. A smooth surface of roughness Rms =0.8 nm was obtained by controlling the morphology of the initial growth layer in a two-step deposition.