Epitaxial Growth of CrO₂ Thin Films on TiO₂(110) Surfaces

Chromium dioxide films on TiO 2 (110) single crystals have been grown by using chemical vapor deposition. The average growth rate was ∼1.8 nm·min - 1 . Powder X-ray diffraction indicated that the films were highly (110) textured. X-ray photoelectron spectroscopy showed that the CrO 2 films were continuous and no other chromium oxides were present. The CrO 2 films were composed of grains typically 200−300 nm in diameter and appeared consistent with the rutile crystal structure. Atomic force microscopy suggested that the films were relatively rough, with a root-mean-square roughness of ∼114 nm for an 850 nm thick film. The resistivity at room temperature was found to be ∼137 μΩ·cm which decreased to ∼16 μΩ·cm at 5 K, consistent with metallic behavior. The films were ferromagnetic with a Curie temperature of 398 K.