Structural characterisation of sol-gel SrBi2Nb2O9 thin film deposited on (001) SrTiO3 single crystal

SrBi2Nb2O9 (SBN) thin films with thickness close to 30 nm were deposited on single crystalline (001) SrTiO3 (ST) substrate by sol-gel spin-coating. Af ter deposition, the films annealed for 30 min at several temperatures (500, 550, 600, 650 and 700 degrees C) were studied by X-ray diffraction using a home-made diffractometer operating in asymmetric reflection geometry. Crys tallisation of the precursor as pure SrBi2Nb2O9 occurs between 500 and 550 degrees C. The normal orientation of the film occurs at 550 degrees C, i.e. at the very beginning of the crystallisation process. Rocking curves of (0 010) lines show their full widths at half maximum (FWHM) decrease from 2.5 degrees (550 degrees C) to 1.8 degrees (700 degrees C), indicating that the small remaining disorientation decreases with increasing annealing tempera ture. A full phi-scan study of selected reflections showed that the film is heteroepitaxied on the substrate such as (001)(SBN)//(001)(ST) and [100](S BN)//[110](ST). (C) 1999 Elsevier Science Limited. All rights reserved.