The ion beam-induced migration of an implanted impurity was studied by using a phenomenological model that involved diffusion of the impurity, and vacancies, and assumed a coupling between their motions. The redistribution of implanted Mn, Fe and Ni was observed by using Rutherford back-scattering spectroscopic techniques and was analyzed by using the above model. The implantation was carried out by using an energy of 200keV and a dose of 1016/cm2 at temperatures ranging from 77 to 473K. Coupled continuity equations for implanted atom and vacancy fluxes were solved in order to obtain theoretical fits to experimentally measured concentration/depth profiles. An effective diffusion coefficient which described radiation-induced thermal and athermal processes was deduced from the theoretical fits, and was found to have a value that was some orders of magnitude higher than the normal diffusion coefficient.

D.C.Kothari, V.N.Kulkarni, A.Miotello, L.Guzman, G.Linker, B.Strehlau: Surface and Coatings Technology, 1996, 83[1-3], 88-92