Generation of Ammonia in a Pulsed Hollow Cathode Discharge Operated in an Ar/H/N Gas Mixture Detected by Fourier Transform Infrared.

A hollow cathode discharge with a copper nickel cathode (Cu50Ni50) was operated in an Ar/H/N gas mixture. Optical emission spectroscopy revealed the formation of NH radicals, which serve as precursors for NH formation. Ion mass spectrometry showed the formation of NH and NH ions indicating NH formation.

Surface Stoichiometry and Depth Profile of Ti-CuN Thin Films Deposited by Magnetron Sputtering.

We report the surface stoichiometry of Tix-CuyNz thin film as a function of film depth. Films are deposited by high power impulse (HiPIMS) and DC magnetron sputtering (DCMS). The composition of Ti, Cu, and N in the deposited film is investigated by X-ray photoelectron spectroscopy (XPS).

Spectroscopic Study of Plasma Polymerized a-C:H Films Deposited by a Dielectric Barrier Discharge.

Plasma polymerized a-C:H thin films have been deposited on Si (100) and aluminum coated glass substrates by a dielectric barrier discharge (DBD) operated at medium pressure using C₂H/Ar ( = 2, 4, 6) gas mixtures. The deposited films were characterized by Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS), Raman spectroscopy, and ellipsometry. FT-IRRAS revealed the presence of ³ and ² C-H stretching and C-H bending vibrations of bonds in the films.

Effects of reactive oxygen species on single polycation layers.

Positively charged, branched polyethylenimine (PEI) adsorbed onto silicon wafers and silica surfaces are attacked by free hydroxyl radicals. With AFM colloid probe technique, the surface forces between PEI layers are measured. Force profiles show that an electrostatic repulsion dominates the surface forces between freshly deposited PEI layers.

In vivo examination of the local inflammatory response after implantation of Ti6Al4V samples with a combined low-temperature plasma treatment using pulsed magnetron sputtering of copper and plasma-polymerized ethylenediamine.

Copper (Cu) could serve as antibacterial coating for Ti6Al4V implants. An additional cell-adhesive layer might compensate Cu cytotoxicity. This study aimed at in vitro and in vivo evaluation of low-temperature plasma treatment of Ti6Al4V plates with Ti/Cu magnetron sputtering (Ti6Al4V-Ti/Cu), plasma-polymerized ethylenediamine (Ti6Al4V-PPEDA), or both (Ti6Al4V-Ti/Cu-PPEDA).

Analysis of the release characteristics of cu-treated antimicrobial implant surfaces using atomic absorption spectrometry.

New developments of antimicrobial implant surfaces doped with copper (Cu) ions may minimize the risk of implant-associated infections. However, experimental evaluation of the Cu release is influenced by various test parameters. The aim of our study was to evaluate the Cu release characteristics in vitro according to the storage fluid and surface roughness.

Role of nitrogen in the formation of HC-N films by CH(4)/N(2) barrier discharge plasma: aliphatic tendency.

We have studied the influence of nitrogen on the chemical properties of the hydrogenated carbon nitride (a-CN(x):H) film deposited by CH(4)/N(2) dielectric barrier discharge (DBD) plasma. X-ray photoelectron spectroscopy (XPS) indicates that carbon and nitrogen form an unpolarized covalent bond in these C-N(x) materials, and the observed chemical shift in the C 1s and N 1s binding energy is explained with respect to N 1s incorporation. Furthermore, the average nitrogen content (N/C approximately 0.

Development of metal nanocluster ion source based on dc magnetron plasma sputtering at room temperature.

A simple and cost effective nanocluster ion source for the deposition of size selected metal nanocluster has been developed based on the dc magnetron discharge (including pulsed dc discharge). The most important and interesting feature of this cluster source is that it is working at room temperature, cooled by chilled water during the experiment. There is no extraction unit in this device and the cluster streams flow only due to the pressure gradient from source chamber to substrate via quadrupole mass filter.

Flow of nanosize cluster-containing plasma in a magnetron discharge.

A magnetron source of silver clusters captured by an argon flow with the quadrupole mass filter is used for the analysis of charged clusters after an orifice of the magnetron chamber, and the size distribution function follows from the analysis of clusters deposited on a silicon substrate by an atomic force microscope. Cluster charge near an orifice results from attachment of ions of a secondary plasma that is a tail of a magnetron plasma, and the cluster charge is mostly positive. The character of passage of a buffer gas flow with metal clusters through an orifice is studied both theoretically and experimentally.

Development of dielectric barrier discharge plasma processing apparatus for mass spectrometry and thin film deposition.

Cost effective and a very simple dielectric barrier discharge plasma processing apparatus for thin film deposition and mass spectroscopic analysis of organic gas mixture has been described. The interesting features of the apparatus are the construction of the dielectric electrodes made of aluminum oxide or alumina (Al(2)O(3)) and glass and the generation of high ignition voltage from the spark plug transformer taken from car. Metal capacitor is introduced in between ground and oscilloscope to measure the executing power during the discharge and the average electron density in the plasma region.

Chemical reaction studies in CH4/Ar and CH4/N2 gas mixtures of a dielectric barrier discharge.

Chemical reactions in a dielectric barrier discharge at medium pressure of 250-300 mbar have been studied in CH(4)/Ar and CH(4)/N(2) gas mixtures by means of mass spectrometry. The main reaction scheme is production of H(2) by fragmentation of CH(4), but also production of higher order hydrocarbon molecules such as C(n)H(m) with n up to 9 including formation of different functional CN groups is observed. Formation of C(2)H(2), C(2)H(4), and C(2)H(6) molecules has been investigated in some detail.