Change In Total Angular Momentum Within The Z³F⁰ Titanium Excited StateInduced By Collisions With Hydrogen And Nitrogen Molecules

Abstract

Collisions that produce a change in the total angular-momentum and quenching processes involving the triplet z3F titanium excited level and diatomic molecules have been studied by laser perturbation and time-resolved spectroscopy. The thermally averaged total angular-momentum changing cross sections (za-z3F)inunitsof10-16cm2are'042=3.2+l, 1.4+0.5; 743= 13.3+2, 6.8+1; 032 =19.0 _.+ 2, 7.2 _+ 1, respectively, for nitrogen and hydrogen colliding partners.Large quenching cross sections are obtained, as OQ N2 53 7, and r2 38 _+ 4 in units of 10 -16 cm2. These results are discussed in relation with p'evious measurements dealing with titanium--noble-gas collisions, and with available published results.

Plasma and nitrides: application to the nitriding of titanium

“…The discharge was created by either a 40 MHz or a 13.56 MHz generator, delivering power up to 1 kW, through inductive coils. The working pressure was 10 to 30 mbars and the NH3 flow rate ranged from 0.2 to 0.6 l/min. The substrate was held perpendicularly to the flux as illustrated on figure 2.…”

Plasmas : Sources of Excited, Dissociated and Ionized Species. Consequences for Chemical Vapor Deposition (Cvd) and for Surface Treatment

“…Similarly, Tic14 and N2 can be efficiently dissociated by using a glow discharge, the substrate temperature may then remain at around 200 to 500 ' C [g]. For both methods, an efficient deposition of TiN requires first the formation of titanium atoms, the transport of these atoms (convection and/or diffusion) in a reactive medium leading either to the formation of TiN in volume and deposition of the formed compound onto the surface, or to the formation of the TiN molecule by surface atom recombination reaction onto the surface [14]. For both processes, it can be interestigg to polarize the substrate negatively relative to the plasma in order to grow the layer under ion bombardement.…”