Epitaxial film growth of chromium dioxide by low pressure chemical vapor deposition using chromium carbonyl

Epitaxial chromium dioxide (CrO2) thin films have been deposited by low pressure chemical vapor deposition (LPCVD) on (100) TiO2 substrates using the precursor chromium hexacarbonyl (Cr(CO)6) within a narrow temperature window of 380–400 °C. Normal θ–2θ Bragg x-ray diffraction results show that the predominant phase is CrO2 with only a small amount of Cr2O3 present, mostly at the film surface. The LPCVD films have a reasonably smooth surface morphology with a root mean square roughness of 4 nm on a scale of 5 μm. Raman spectroscopy confirms the existence of rutile CrO2 in the deposited films, while transmission electron microscopy confirms the single-crystalline nature of the films. The LPCVD films showing a dominant CrO2 phase exhibit clear uniaxial magnetic anisotropy with the easy axis oriented along the c direction.