Structural characteristics of RF-sputtered BaTiO3 thin films

In this work some structural characteristics of the thin films deposited by a radio frequency-magnetron sputtering technique from a hot pressed BaTiO3 ceramic target were studied. The Ba/Ti ratio was measured by means of X-ray fluorescence in order to determine the real chemical composition of the films. The results showed that this ratio varied along the radial axis of the discharge. Besides, the evolution in phase composition of the annealed films as a function of the thermal treatment conditions (temperature and plateau) as well as the structural characteristics (unit cell parameter and crystallite size) were investigated by X-ray diffraction (XRD). Infrared (IR) and Raman spectroscopies were used in order to obtain more details about the distorted structure of such fine-grained thin films. In the case of these films, Raman spectroscopy carried out from 99 to 473 K did not emphasize steep, distinct transitions between the different polycrystalline BaTiO3 forms when compared with the bulk BaTiO3. (C) 2001 Elsevier Science B.V. All rights reserved.