Films of Ti-deficient SrTixO3, where x was less than unity, were grown onto (100)-oriented SrTiO3 monocrystalline substrates by means of the radio-frequency magnetron sputtering of stoichiometric targets. The Ti/Sr cation ratio, x, was determined by using Rutherford back-scattering and energy dispersive X-ray analysis in a scanning electron microscope. In order to obtain information on the Ti/O ratio, X-ray absorption spectroscopy was also carried out. An investigation was made of films with x = 0.98, 0.95 or 0.89. Epitaxial growth and lattice imperfections were characterized by means of X-ray diffraction, electron diffraction and high-resolution transmission electron microscopy. The films had a tetragonal structure, with a maximum mosaic spread of about 0.1º. The c-axis was oriented perpendicularly to the substrate surface, and the c-lattice parameter increased with decreasing x-value. For x = 0.89, the Ti deficiency was compensated mainly by a change in the site occupation of the cation sub-lattices, together with O vacancies. That is, by the formation of SrTi and VO point defects. When x was less than 0.95, the intergrowth of homologues in a series of Ruddlesden-Popper phases, Srn+1TinO3n+1, was observed. The dielectric properties of the films were explained in terms of (SrTiVO) defect complexes.

Structural Properties of Slightly Off-Stoichiometric Homoepitaxial SrTiO3 Thin Films. D.Fuchs, M.Adam, P.Schweiss, S.Gerhold, S.Schuppler, R.Schneider, B.Obst: Journal of Applied Physics, 2000, 88[4], 1844-50