N, H and C-atoms Concentrations in Flowing Afterglows of Microwave R/N\(_2\)-H\(_2\) and R/N\(_2\)-CH\(_4\) Discharges with R=N\(_2\), He, Ar and Their Applications to TiO\(_2\) Surface Nitriding

Abstract

Flowing afterglow plasmas have found their interest in soft surface treatments of sensitive materials in life science as the sterilization of medical instruments. Variations of N,H and C-atoms density has been determined along the reduced pressure flowing afterglows of microwave R/N₂-H₂ and R/N₂-CH₄ discharges with R=N₂, He and Ar. Density of H and C-atoms and other nitrogen-active species such as N₂(A), N₂(X,v>13),N₂⁺,NH,N(²D), CN were obtained from that of N-atoms calibrated by NO titration, using the method of band intensity ratios in several conditions (between early and late afterglows). It has been obtained the density of O-atoms and NO molecules coming from air impurities. It has been deduced the wall destruction probability of H,O and C-atoms on the quartz afterglow tube: \(\gamma\)_H^R,N2=10^-3,\(\gamma\)o^R,N2=(0.4-1) 10^-3 and \(\gamma_C^{N2}\)=(0.7)10^-3. The effects of H and C-atoms on N-atoms inclusion inside TiO₂ surfaces are reported.