Advanced carbon-based material C[sub 60] modification using partially ionized cluster and energetic beams

The effect of transport ratio and ion energy on the mechanical properties of IBAD niobium nitride coatings

Pathway Clustering of the Up-regulated Genes in the Stimulated Rice Seedlings that Germinating from the Seeds Implanted by the Low-Energy Nitrogen Ion

Changing the tribological performance of steels using low energy, high temperature nitrogen ion implantation

Carbon nitride films have been formed on Si(100) substrates by laser ablation of graphite under a low energy nitrogen ion beam bombardment. Data of Raman shift and x-ray photoelectron spectroscopy indicate the existence of carbon-nitrogen bonds in the films. Time-of-flight measurements suggest the existence of paracyanogen-like materials, such as C4N4, in the films. High energy backscattering spectrometry has shown that the percentage of N content in the film is 41% or so. The x-ray diffraction and transmission electron micrograph measurements have also been taken to characterize the crystal properties of the obtained films. Qualitative tests indicate the films of high Vickers hardness Hv, and of good adhesion to the silicon substrates.

The ion beam interaction with very thin films (0.5 μm thickness) of a fundamental polymer, polystyrene, was investigated by means of radiation chemistry. Radiation effects on solubility of spin-coated polystyrene films were measured for hydrogen, helium and nitrogen ion beams (0.4 - 3.3 MeV). Measurements were also carried out for 20 keV electrons. By using ion beam pulse radiolysis system, the transient phenomena excited by energetic ion beams were investigated. The time profiles of the excimer fluorescence from ion irradiated polystyrene thin film were measured for hydrogen, helium and nitrogen ions (0.6 - 2.8 MeV). The results for energetic ions were compared with those for low LET radiation, such as fast electron or gamma-ray. Very large differences in radiation effects on solubility and some differences in transient phenomena were found and discussed from the view point of high density electronic excitation.

Low Energy Nitrogen Ion Beam Increases the Roegneria Yield by Improving the Protection Enzymes Activity and Photosynthesis

In order to generate a mutant of Bacillus subtilis with enhanced surface activity through low energy nitrogen ion beam implantation, the effects of energy and dose of ions implanted were studied. The morphological changes in the bacteria were observed by scanning electron microscope (SEM). The optimum condition of ions implantation, 20 keV of energy and 2.6×1015N+/cm2 in dose, was determined. A mutant, B.s-E-8 was obtained, whose surface activity of 50-fold and 100-fold diluted cell-free Landy medium was as 5.6-fold and 17.4-fold as the wild strain. The microbial growth and biosurfactant production of both the mutant and the wild strain were compared. After purified by ultrafiltration and SOURCE 15PHE, the biosurfactant was determined to be a complex of surfactin family through analysis of electrospray ionization mass spectrum (ESI/MS) and there was an interesting finding that after the ion beam implantation the intensities of the components were different from the wild type strain.

1490. A low energy nitrogen ion beam: R H Prince, Toronto University, Ontario, Canada, May 1965, 70 pages

This work presents data and calculations of (HCP)‐to‐gamma TLD‐100 thermoluminescent efficiencies. Dosemeters were irradiated with low energy hydrogen, helium, carbon, nitrogen and oxygen ions. For nitrogen and oxygen two energies, corresponding to “mirror” values below and above the Bragg peak energy, were used to measure TL efficiencies for the same linear energy transfer (LET) entrance value. Efficiency results, both as a function of LET and energy, show distinct curves for each ion species. For energies above the Bragg peak energy, measurements show the well known tendency, efficiency values decrease with increasing LET. Data for energies lower than the Bragg peak display the opposite, efficiency increases with increasing LET. Results presented as a function of incident energy show that efficiency decreases with decreasing energy. For nitrogen and oxygen ions, the “mirror” measurements at higher energy (above the Bragg peak) are found to be 1.45 times greater than their low energy counterparts. Theoretical predictions based on Modified Track Structure Theory (MTST) show agreement with data within 40 % and predict the observed behavior, higher efficiency for higher ion energy.

Depth resolved positron annihilation measurements were carried out on 85 keV and 1 MeV nitrogen ion implanted InP samples. The defect sensitive S-parameter and R-parameter values for the low energy implantations confirm the presence of monovacancies up to a dose of 1015 cm−2 and coexistence of monovacancies and divacancies for 1016 cm−2 dose sample. Corroborative glancing incidence x-ray diffraction measurements on the highest dose sample revealed that the sample is amorphized. For high energy implantation, it is found that vacancy-defects are present right from the near-surface region and these defects are identified to be monovancancies, based on the observed S- and R-parameters. A comparison of the results for the low and high energy implantations is made.

Plasma source ion nitriding has emerged as a low-temperature, low-pressure nitriding approach for low-energy implanting nitrogen ions and then diffusing them into steel and other alloys. In this work, 1Cr18Ni9Ti (18–8 type) austenitic stainless steel was treated at a process temperature from 280 to 480 °C under an average nitrogen implantation dose rate (nitrogen ion current density) of 0.44–0.63 mA cm−2 during a nitriding period of 4 h. The nitrided surfaces of the stainless steel were characterized using Auger electron spectroscopy, electron probe microanalysis, glancing angle X-ray diffraction, and transmission electron microscopy. Below 300 °C, a high nitrogen f.c.c. phase (γN) and an ordered f.c.c. phase (γ′) mixed phase and a γN and a nitrogen-induced martensite (ɛ′N) mixed phase were obtained respectively under lower and higher nitrogen implantation dose rates. In the range of 300–450 °C a single γN phase was observed under various nitrogen implantation dose rates. Above 450 °C, the decomposition of the γN phase to a CrN phase with a b.c.c. martensite was obtained. Phase states and phase transformations in the plasma source ion nitrided 1Cr18Ni9Ti stainless steel at the low process temperatures are dependent on all the process parameters, including process temperature, nitrogen implantation dose rate, nitrogen ion energy, and processing time, etc.. The process parameters have significant effects on the formation and transformation of the various phases.

In this paper, we report the deposition of graphite multilayer containing nitrogen covering nanometric nickel particles. In-situ photoelectron emission spectroscopy (XPS) reveals the presence of nitrogen in the carbon layer covering the nickel particles. The field emission properties of the structures are reported. Atomic force microscopy displays regular domelike structures. Raman spectroscopy shows the characteristic frequencies associated with graphite and disordered structures. High-resolution transmission electron microscopy confirms the presence of multiwall well-organized graphite layers covering the nickel particles. Disorder increases on increasing nitrogen content. The samples were prepared in-situ by depositing first a few atomic layers of nickel and subsequent islands formation by thermal annealing. Then, an argon ion beam bombards an ultrapure carbon target and simultaneously the growing film is assisted with a second low-energy nitrogen ion beam (ion beam assisted deposition).

ESCA analysis identifies that the different functional groups of nitrogen compounds have been conbined on the PET surfaces, when modified by the air plasma and the argon plasma. In particular, the double N15 peaks occur on the PET surface after 5 minutes treatment by the low temperature argon plasma. The second peak-N15 is considered as the contribution of nitrogen oxides. The double peaks PET-N15 structure does not result by bombardment with low energy nitrogen ions and argon ions, which indicates that the effect can not be attributed to the action of low energy ion alone.

Influence of N concentration on structure and properties of (AlCrMoTiV)Nx films by co-filter cathodic vacuum arc deposition

Interaction processes of heavy ions and ionized matter have been investigated experimentally. A Monte‐Carlo code to simulate charge exchange and energy loss processes in a plasma environment has been developed to plan the experiments, to analyze the results, and to investigate the influence of magnetic fields on the particle trajectories inside the plasma target. The first results of the beam plasma interaction experiments are:•The stopping power of ionized matter is increased compared to that of cold, non‐ionized matter. This effect is especially pronounced at low ion energies (E<100 keV/u) where an enhancement factor of up to 40 has been observed. At higher energies (E≳1 MeV/u) this effect is less dramatic, but is still on the order of 2−3, depending on the ion species.•The charge state of ions traversing a fully ionized plasma is increased due to reduced capture cross sections of free plasma electrons.•It is possible to focus intense heavy ion beams of high magnetic rigidity using a plasma lens. This ideal focusing device achieves a high focusing power for ion beams almost comparable to optical systems for intense beams from high power lasers.•Energetic ion beams are very well suited to heat cylindrical target volumes and to create a dense plasma. The characteristic inner‐shell target and projectile x rays provide a tool to analyze the hydrodynamic behavior of beam heated targets with space and time resolution.