Study of Concentration-depth Profiles of the Titanium and Nitrogen Ions by SRIM/TRIM Simulation

In this research, the concentration-depth profiles reached by titanium and nitrogen particles, on the surface of AISI/SAE 1020 carbon steel substrates, by using of ion implantation technique, are studied. The ions are surface deposited by means of high voltage pulsed discharges and electric arc discharge under high vacuum conditions. The concentration and position distribution of the metallic and non-metallic species are obtained by simulation of the interaction of ions with the matter, stopping and ranges of ions in the matter, by the computer program transport of ions in matter. The implantation dose is calculated from the discharge data and the previously established study parameters in this work. From the simulation results, the depth profiles demonstrated that titanium and nitrogen ions may reach up to 300 Å and 600 Å and concentrations of 1.478 x 1016 ions⁄cm2 and 2.127 x 1016 ions⁄cm2, respectively. The formation of titanium microdroplets upon the surface of the substrates is identified from the micrographs obtained by the scanning electron microscopy technique; furthermore, the presence of titanium and nitrogen implanted on the surface of the substrate is verified through the elemental composition analysis by the energy dispersive spectroscopy, validating the effect of ion implantation on ferrous alloys.

Increased durability of selected tools used in the rubber industry by hybrid treatment

This research concerns hybrid layers of the CrC+CrN type, produced on the tool steel surface in subsequent processes, diffusion chromizing, carried out by inexpensive and technologically simple powder method, combined with the next arc evaporation treatment Arc PVD (arc evaporation physical vapour deposition), made for the deposition of chromium nitride coatings. Investigations of the microstructure of hybrid layers, as well as of their phase composition and concentration depth profiles of elements in diffusion zone of these layers, were carried out. In addition, the layers hardness, their tribological properties (pin-on-disk method) and corrosion resistance have been determined. It has been shown that hybrid layers of the CrC+CrN type are characterized by very good tribological properties at ambient temperature 25°C and at temperature 100°C as well as by very good resistance to corrosion in a solution containing chlorine ions.

Особенности электрохимического вольт-фарадного профилирования арсенид-галлиевых светоизлучающих и pHEMT-структур с квантово-размерными областями

GaAs light-emitting (LED) and HEMT structures with δ-doped regions, InGaAs/GaAs quantum wells, and surface layers of InAs/GaAs quantum dots were studied by means of the electrochemical capacitance- voltage profiling technique. The concentration depth profiles of free charge carriers were obtained. Charges accumulated in quantum wells and quantum dots, as well as the doping levels of the emitter and δ layers were determined. The band structure and free carrier density distribution over the depth of the samples with different quantum well geometry were simulated. The specific features of electrochemical capacitance- voltage profiling in different heterostructure types are analyzed. A method of integration of capacitance- voltage curves at each etching stage was suggested. This method provides the efficient separation of responses from closely located layers, particularly the quantum well and δ layer.

Laser ion implantation of Ge in SiO2 using a post-ion acceleration system

This work reports a comparative study of laser ion implantation mainly performed at the Nuclear Physics Institute in Rez (Czech Republic), National Institute of Nuclear Physics (Italy), and the Plasma Physics Laboratory at the University of Messina (Italy) using different approaches. Thick metallic targets were irradiated in vacuum by a focused laser beam to generate plasma-producing multi-energy and multi-species ions. A post-acceleration system was employed in order to increase the energy of the produced ions and to generate ion beams suitable to be implanted in different substrates. The ion dose was controlled by the laser repetition rate and the time of irradiation. Rutherford backscattering analysis was carried out to evaluate the integral amount of implanted ion species, the concentration–depth profiles, the ion penetration depth, and the uniformity of depth profiles for ions laser implanted into monocrystalline substrates. The laser implantation under normal conditions and in post-acceleration configuration will be discussed on the basis of the characterization of the implanted substrates.

PROPERTIES OF DUPLEX LAYERS PRODUCED IN A VACUUM CHROMIZING PROCESS ON STEEL COVERED WITH COBALT ALLOY

The paper presents the results of examinations of the structure and properties of duplex layers of the CrC+(Co-W) type, produced in a vacuum chromizing process on a tool steel surface covered with Co-W electrolytic alloy. A comparison of the CrC+(Co-W) type duplex layers with the CrC type single carbide layers, produced in vacuum chromizing process, were performed. Studies of layers thickness, their hardness, structure, and concentration depth profiles of elements in the diffusion zone of these layers were carried out. Tribological properties of the layers and corrosion resistance were determined. It has been proven that the wear resistance by friction of the CrC+(Co-W) type duplex layers, produced by means vacuum chromizing of tool steel covered with Co-W alloy electrolytic coating, is as good as single carbide layers of the CrC type, but their corrosion resistance is higher.

Concentration Profile Simulation of SiC/Si Heterostructures

Computer simulation of the concentration profiles evolution in SiC/Si heterostructures during growth and subsequent ion sputtering is presented. Simulation is based on a complex self-consistent approach combining kinetic and ballistic methods. Within the framework of the proposed method concentration depth profiles in SiC/Si heterostructure with pre-deposited Ge impurity are calculated and compared with experimental sputtering profiles obtained by secondary ion mass spectrometry.

Applied-Information Technology in Concentration Depth Profile of Multi-Charged Mo Ion Implantation

Monte Carlo computer simulations based on the binary collision approximation, TRIDYN program, have been applied to calculate the concentration depth profiles of implanted multi-charged molybdenum ions in H13 steel. The sputtering effect of a high dose ion implantation and influence of multi-charged ions on the concentration depth profile of implanted molybdenum ions can both be considered in the TRIDYN simulation. For the Monte Carlo computer simulation, the chosen pseudo-projectiles are 500000. The chosen extraction voltages are 48kV and 25kV, respectively, and an implantation doses of 5×1017cm-2 to compare the results which have been published related to molybdenum ion implantation. TRIDYN program is better than SRIM program in the calculation of the concentration depth profiles of implanted multi-charged ions. And the calculation result of the TRIDYN program is different from the experiment result. The other factors of affecting the concentration depth profile have also been discussed finally.

The Factors Affecting the Surface Properties of W-Implanted H13 Steel

The surface properties of W-implanted H13 steel are investigated using pulse multi-charged ion implantation. Computer simulations based on the binary collision approximation, TRIDYN, have been applied to calculate the concentration depth profiles of implanted tungsten ions in H13 steel. The calculated result by TRIDYN program is compared with that from experimental results. The factors affecting the surface properties of W-implanted H13 steel have been discussed. The radiation enhanced diffusion induced by spike is the main factor affecting the concentration depth profile. Compared with single energy ion implantation, the multi-charged ion implantation will make the concentration gradient become small, which is conducive to the formation of a kind of relatively uniform surface structure, and further improve the wear resistance of H13 steel.