Laser Plasma-Chemical Deposition of Hafnia-Doped Solid Silicon Carbonitride Coatings

Abstract

Solid hafnia-doped silicon carbonitride coatings are synthesized using laser plasma in a high-speed argon flow from hexamethyldisilazane (HMDS) Si₂NH(CH₃)₆ and hafnium dipivaloylmethane Hf(dpm)₄ vapor mixture. The coatings are characterized by X-ray photoelectron, IR, and Raman spectroscopy techniques. The structural studies are carried out by powder XRD; the coating hardnesses are measured by nanoindentation. The hardness of the coatings synthesized on stainless steel from a HMDS and Hf(dpm)₄ mixture is 21-24 GPa at a Hf(dpm)₄ concentration of up to 2.5 wt. % and decreases to 7 GPa if the Hf(dpm)₄ content increases in a mixture to 4.5 wt. %.