Visible-laser photodeposition of chromium oxide films and single crystals

Visible-laser deposition reactions of the chromyl chloride vapor, CrO2Cl2, have been developed for direct writing of chromium oxides. Deposition at low laser power is by photolysis of adsorbed CrO2Cl2 molecules. Higher powers initiate deposition photochemically and continue it with a combined photolytic/pyrolytic reaction, simultaneously inducing a solid phase conversion of the deposited film. Mixed Cr2O3/CrO2 thin films of 1 nm to several micrometer thickness, as well as 1-mm-long single crystals of Cr2O3, were grown, the latter at rates up to 3 μm/s. The thin films are strongly ferromagnetic. Mass spectrometer and optical transmission measurements show that surface kinetics dominate the nucleation and growth rates.