Phase formation in double oxide films of Hf–La–O system

• The structure of LaxHf1−xOy solid solutions films produced by MO CVD depends on lanthanum concentration.
• The films of fluorite-like structure occupy the area ∼4• The films with 18 at% La reveal the pyrochlore structure.
• A mixture of monoclinic HfO2 and cubic solid solution phases were formed at CLa≤4 at%.
• Two-phase films consisting of La2Hf2O7 (pyrochlore) and La2O3 (cubic) were observed at CLa>25 at%.

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 β-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 ∼4 to 18 at% of.The films comprising a mixture of monoclinic HfO2 (equilibrium) and cubic solid solution phases have been formed at CLa≤4 at%. Two-phase films consisting of La2Hf2O7 (pyrochlore) and La2O3 (cubic) have been observed at lanthanum concentration (CLa)>25 at%.