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The article presents the results of studies of the features and regularities of high-intensity nitrogen ion implantation into titanium using repetitively-pulsed beams with high average power densities. It is shown that the method of low-energy high-intensity nitrogen ion implantation at current densities of 180, 140, 60, and 10 mA/cm2 makes it possible to obtain wide ion-doped layers in titanium. The regularities of changes in both thickness and elemental composition of ion-doped layers depending on the ion current density have been established. It has been established that a wide diffusion layer is observed at ion current densities from 60 to 180 mA/cm2. Nitrogen concentration in the diffusion layer increases with an increase in the ion current density. The article presents the transmission electron microscopy data showing that the modified layers at a depth of 10 μm consist of α-Ti, in the volume of which nanosized particles of δ-TiN with average size of 15.4 nm crystallize. [ABSTRACT FROM AUTHOR]

A method for calculating diffusion coefficients DFe and DCr and interdiffusion coefficient in an irradiated Fe–Cr alloy is proposed. The substitution of the values of the self-diffusion coefficient of iron into Darken's equation refined by Manning, which are determined with allowance for the radiation enhanced diffusion and the formation of vI and iI complexes (v is a vacancy, i is a self-interstitial atom, and I is an impurity atom), makes it possible to obtain the temperature and concentration dependences of DFe, DCr, and D at various rates of generation of radiation point defects (dpa/s). [ABSTRACT FROM AUTHOR]

Crystalline and preamorphized isotope multilayers are utilized to investigate the dependence of ion beam mixing in silicon (Si), germanium (Ge), and silicon germanium (SiGe) on the atomic structure of the sample, temperature, ion flux, and electrical doping by the implanted ions. The magnitude of mixing is determined by secondary ion mass spectrometry. Rutherford backscattering spectrometry in channeling geometry, Raman spectroscopy, and transmission electron microscopy provide information about the structural state after ion irradiation. Different temperature regimes with characteristic mixing properties are identified. A disparity in atomic mixing of Si and Ge becomes evident while SiGe shows an intermediate behavior. Overall, atomic mixing increases with temperature, and it is stronger in the amorphous than in the crystalline state. Ion-beam-induced mixing in Ge shows no dependence on doping by the implanted ions. In contrast, a doping effect is found in Si at higher temperature. Molecular dynamics simulations clearly show that ion beam mixing in Ge is mainly determined by the thermal spike mechanism. In the case of Si thermal spike, mixing prevails at low temperature whereas ion beam-induced enhanced self-diffusion dominates the atomic mixing at high temperature. The latter process is attributed to highly mobile Si di-interstitials formed under irradiation and during damage annealing. [ABSTRACT FROM AUTHOR]