STRUCTURAL-PROPERTIES OF LINBO3 THIN-FILMS GROWN BY THE PULSED-LASER DEPOSITION TECHNIQUE

LiNbO3 thin films have been deposited onto R-cut and C-cut single crys talline sapphire substrates (alpha-Al2O3, (1 $($) over bar$$ 102) and (0001)) by the pulsed laser deposition technique at different oxygen p ressures and substrate temperatures. Thin film composition and structu re have been determined using Rutherford backscattering spectroscopy ( RES) and X-ray diffraction experiments. The atomic composition is depe ndent on the oxygen pressure in the range 0.5-1.3 mbar. At pressures l ower than 1.3 mbar, we have observed a deviation from the stoichiometr y. Nearly stoichiometric thin films have been obtained for a pressure equal to 1.3 mbar. For that pressure, the atomic composition does not depend on the substrate temperature in the range 650-800 degrees C. Un der optimised conditions the (1 $($) over bar$$ 102) and (0001) prefer ential orientations of growth have been obtained on (1 $($) over bar$$ 102) and (0001) sapphire substrates, respectively.