Reactivity of Cr(CO)₆ in atmospheric pressure CVD processes for the growth of various metallurgical coatings

Metalorganic precursors allow a significant decrease of the deposition temperature in CVD processes. When they are employed under atmospheric pressure and using direct liquid injection delivery systems, new processes can be developed for the growth of metallurgical coatings. However, even for a single precursor the great variety of reactive gas phase leads to various coatings with different properties. Original nanocrystalline CrC_xO_y and CrN_xO_y films were deposited in a laminar flow reactor by MOCVD and DLICVD using Cr(CO)₆ as molecular precursor in the temperature range 285-450 °C. Pyrolysis was carried out in different ambient including N₂, H₂, NH₃, THF, and toluene. The influence of the various atmosphere on the composition, structure and, consequently, mechanical properties and corrosion behavior of these coatings is discussed.