Inelastic energy loss of Ar ions scattered Al2O3 surface under grazing incidence

In this paper presents the investigation of the surface Al2O3 by ion scattering spectroscopy. The trajectory of small angle scattered ions calculated by the method of binary collision approximation. It was found dependence of inelastic energy loss and trajectories of scattered ions. The value of inelastic energy loss scattered ions almost depend to the angle of incidence and the geometrical parameters of surface semichannels.

INVESTIGATION OF DEFECT INP(001) SURFACE BY THE METHOD OF LOW ENERGY ION SCATTERING

Investigation of grazing scattering of 3 keV Ar+ and Xe+ ions from the defect surface InP(001) are reported. Computer simulations based on the binary collision approximation permit one to carry out a quantitative analysis of data. It is determined that energy distributions of reflected ions directly depend on the defect structure of the topmost surface layer, and these defects form some peaks in low energy part of energy distribution.

Channeled Implantations of p-Type Dopants into 4H-SiC at Different Temperatures

Channeling of B and Al ions in 4H-SiC(0001), has been investigated by secondary ion mass spectrometry (SIMS). Ion implantations have been performed between room temperature (RT) and 600 °C at various fluences. Before implantation, the major crystal axes were determined and the sample was aligned using the blocking pattern of backscattered protons. As expected, the depth distribution of the implanted ions along a crystal direction penetrates much deeper compared to non-channeling directions. At elevated temperatures, the channeling depth for 100 keV Al-ions is decreased due to lattice vibrations. For 50 keV B-ions, the temperature effect is minor, indicating a smaller interaction between target atoms and B. Simulations has been performed using SIIMPL, a Monte Carlo simulation code based on the binary collision approximation, to predict experimental data and get a deeper insight in the channeling process.

Phase shift of solitary wave in a one-dimensional granular chain

In this paper, both the fifth-order Runge–Kutta numerical scheme and binary collision approximation are used to study the phase shift. Both numerical and theoretical results are shown that the solitary wave after head-on collision propagates along the chain behind the reference wave in both even and odd numbers of grain chains. It is the well-known feature of the appearance of the phase shift. Those results are in agreement with the experimental results. Furthermore, it is found that the phase shift is not only related to the collision position of the waves, but also to the position where the time is measured. The value of phase shift increases nonmonotonously with increasing the velocity of the opposite propagation of the wave. Binary collision approximation is applied to analyze the phase shift, and it is found that theoretical results agree well with numerical results, especially in the case of phase shift in odd chain.

Quick calculation of damage for ion irradiation: implementation in Iradina and comparisons to SRIM

Binary collision approximation (BCA) calculation allows for two types of damage calculation: full cascade and quick calculations. Full cascade mode describes fully the cascades while in quick calculations, only the trajectory of the ion is followed and effective formulas give an estimation of the damage resulting from each collision of the ion. We implement quick calculation of damage in the Iradina code both for elemental and multi-component solids. Good agreement is obtained with SRIM. We show that quick calculations are unphysical in multi-component systems. The choice between full cascade and quick calculations is discussed. We advise to favour full cascade over quick calculation because it is more grounded physically and applicable to all materials. Quick calculations remain a good option for pure solids in the case of actual quantitative comparisons with neutron irradiations simulations in which damage levels are estimated with the NRT (Norgett-Robinson and Torrens) formulas.

THE COLLIDING PARTICLES MASS RATIO INFLUENCE ON PECULIARITIES OF LOW-ENERGY ION NEAR-SURFACE IMPLANTATION AT CHANNELING CONDITIONS

In the present work the peculiarities of ion implantation and colliding particles mass ratio influence on the ranges, energy loss and profiles of distribution for 1−5 keV P+ ions channelling in Si(110) and SiC(110) at normal incidence, and 1 keV Be+ and Se+ ions in GaAs(100), as well as 5 keV Ar+ and Kr+ on Cu(001) surface at glancing incidence are carried out by computer simulation in binary collision approximation. It is shown that for paraxial part of a beam the main contribution to the total energy loss comes from inelastic ones. It has been established that the energy loss of ions transmitted through thin crystal and depth profile distributions depend on width of the channel and mass ratio of colliding atoms. It was shown that at grazing surface channeling conditions the main peak of the implanted depth distributions is considerably shallow, the range for Se+ ions is shallower and the half-width of profile for these ions is narrow than that for Be+ ions. The results allow one to select the optimum for implanted depth distributions with demanded shape at narrow near-surface area of crystals obtaining.