Epitaxial growth of zirconium dioxide films on sapphire substrates

Single-crystalline monoclinic ZrO2 films are grown on sapphire-R substrates by a molecular beam epitaxy method, which thicknesses ranging from 1.6 to 20 nm. Ozone gas is introduced into the chamber during the growth so as to oxidize evaporating ZrO or Zr dissociated by electron-beam bombardment. Reflection high-energy electron diffraction patterns show sharp streaks indicating the grown films have good crystallinities and reveal the epitaxial relations between the substrates and the films. In addition, X-ray diffraction and infrared absorption analysis support that monoclinic ZrO2 (001) is grown epitaxially on the sapphire-R (1102) substrate.