Metal Ions In High Temperature Injected Into The Metal Target The Mass Transfer Mechanism

The mass transfer mechanism of metal ions implantation into metal target at elevated temperature was studied systematically by doing the experiments and building up the theoretical model. Firstly, A mass transfer model has been built up for metal ion implantation into metal target at elevated temperature, based on the transport in matter of ions and the radiation enhanced diffusion theory. With the model, the ion implantation process at elevated temperature was simulated by the Monte Carlo method and the local saturation behavior in the crystal target simulated using a maximum allowed atomic fraction. Moreover, the diffusion process was described with the radiation enhanced diffusion theory. Thus the concentration-depth profiles of the implanted species were determined from the diffusion equations for the implanted species and nonequilibrium vacancies, and the radiation enhanced diffusion coefficient was obtained by taking into account the linear annealing defects. The nonequilibrium vacancy source function and the surface sputtering effects were introduced in the diffusion equations. Secondly, Al ions were implanted into Fe target at the temperatures of RT, 250 ?, 500 ?3, at the implanted energy of 120 keV, with the implanted doses of 5X 1016 ions cm2, 1 1017 ions cm2. The phase structure of samples was analyzed by X-ray diffraction analysis (XRD) and the concentration-depth profiles of implanted species were obtained from Rutherford backscattering spectrometry (RBS). According to the results of XRD and RBS the effect of target temperature and implantation dose on mass transfer process was analyzed, which showed that the elevated target temperature affect the mass transfer process by the new intermetallic phase formed during ion implantation at elevated temperature and the increase of implantation dose resulted in the temperature elevated in some part of the target and provided more available vacancies which could improve the diffusion process. Thirdly, the concentration-depth profiles of Al ions implantation into Fe target were calculated at given experimental conditions done in this paper, and the concentration-depth profiles of Cr, Ni, Fe ions implantation into Al target were calculated at different target temperatures, at different implantation energies and with different implantation doses. The calculated results were consistent with the experimental ones.