Metal Organic Chemical Vapor Deposition method (MO CVD) has been developed for LaxHf1-xOy films of an assigned composition by co-deposition from vapors of volatile La and Hf beta-diketonates. The phase composition and structure of films have been investigated by X-ray diffraction (XRD) (synchrotron radiation), Atomic Force Microscope (AFM), Energy Dispersive Spectroscopy (EDS), and X-ray Photoelectron Spectroscopy(XPS) methods. It has been shown that the structure of films depends on lanthanum concentration. The formation of LaxHf1-xOy solid solution films of a cubic (fluorite-like) structure occurs with the lanthanum concentration extending from similar to 4 to 18 at% of. The films comprising a mixture of monoclinic HfO2 (equilibrium) and cubic solid solution phases have been formed at C-La <= 4 at%. Two-phase films consisting of La2Hf2O7 (pyrochlore) and La2O3 (cubic) have been observed at lanthanum concentration (C-La) > 25 at%. (C) 2013 Elsevier B.V. All rights reserved.