Characterization of transport of titanium neutral atoms sputtered in Ar and Ar/N 2 HIPIMS discharges

International audienceIn this work we report on the investigation of the transport behavior of Ti neutral atoms sputtered in a reactive high power impulse magnetron sputtering device used for TiN coating deposition. The time-resolved tunable diode laser induced fluorescence (TR-TDLIF), previously developed to study the transport of tungsten atoms, was improved to measure Ti neutral atom velocity distribution functions. We find that the TR-TDLIF signal has to be fitted using three Gaussian distributions, corresponding to the energetic, thermalized, and quasi-thermalized (atoms with non-zero mean velocity) atom populations. The ability to distinguish populations of atoms and to determine their corresponding deposited flux and energy may be of great interest to control film properties as desired for targeted applications. From the fitting, the vapor transport parameters (flux and energy) are calculated and studied as a function of distance from the target, pressure, and percentage of nitrogen in an Ar/N2 gas mixture. The study focuses on the effect of added nitrogen on the transport of sputtered atoms

Spectroscopic investigation of a temporal post-discharge plasma for iron nitriding

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The use of microwave plasma-assisted CVD on nanostructured iron catalysts to grow isolated bundles of carbon nanotubes

International audienceCatalysts play a key role in the growth of carbon nanotubes. The microwave plasma-assisted chemical vapor deposition (MPACVD) method is now commonly used for directional and conformal growth of carbon nanotubes (CNTs) on substrates. In this work, we report on the effect of H2 plasma pre-treatment on the diameter and density of iron catalyst nanoparticles for different iron layer thicknesses in order to grow isolated bundles of CNTs. Atomic force microscopy shows first that as plasma power density increases, iron nanoparticle diameters decrease, which is due to the increasing of gas dissociation giving more ion bombardment energy, and second that the diameter of nanoparticles decreases with the catalyst thickness. The?growth of CNT was carried out under different CH4 concentrations for different iron film thicknesses. Transmission electron microscopy and Raman spectroscopy show that the synthesized CNT were of good quality and had an outer diameter between 5 and 10?nm

Low frequency d.c. pulsed plasma for iron nitriding

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Time-resolved plasma diagnostics for a better understanding of the improvement of pulsed MWPACVD of diamond

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Characterization of a neutral atomic hydrogen source developed in the perspective of carbon materials etching study

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