Influence of standoff distance on the structure and properties of carbon coatings deposited by atmospheric plasma jet

▶ Carbon coatings (standoff distance 5 mm) are porous with ∼10 GPa hardness. ▶ Coatings (standoff distance >5 mm) are softer with high H (∼25 at.%) and O content. ▶ Decrease of standoff distance yields lower H (7 at.%) and O (5 at.%) concentration. ▶ H is mainly bonded to the sp3 carbon (70-60 at.%) and forms methylene compounds.