Pulsed laser deposition of hard carbon coatings at atmospheric pressure

A technique of vacuum-free deposition of thin films from laser-induced plasma arising upon the ablation of a target by intense laser radiation is proposed and experimentally realised. Experimental results on the deposition of hard carbon coatings onto stainless steel substrates upon evaporation of a graphite target in air by picosecond pulses from a Nd:YAP laser are presented. According to the data of X-ray electron spectroscopy and X-ray diffraction analysis, the films obtained in our experiments consist of sp²- and sp³-bound amorphous carbon with a small admixture of oxygen. The coating was tested for mechanical properties to exhibit excellent results, including nanohardness (12 — 14 GPa on the average, up to 40 GPa locally) and adhesion to the substrate (>60 MPa), undeniably testifying to the promise of this technique.