ion implantation and laser doping are promising tools for the fabrication of films with specified physical, chemical, and mechanical properties on metal and alloy surfaces. in ion-implantation metallurgy, the doping atom is implanted directly into the matrix material to a depth of =0.01-0.1 mum. the structure of ion-doped alloys is determined by the processes that accompany the collision cascades: these processes may be regarded as a rapid hardening of thermal wedges with cooling rates =10/sup 14/ k/s. on the other hand, laser doping involves irradiating a metal coated by a layer of the doping element. the laser beam melts the surface layer of the metal, the elements are mixed in the liquid phase, and the melt crystallizes rapidly. irradiation by nanosecond laser pulses produces a molten layer =1 mum deep, and cooling rates of =10/sup 10/ k/s are achieved. immiscibility of the components in the liquid phase may hinder the incorporation of the dopant in the surface layer of the original metal, and laser annealing cannot be used in this case. the authors analyze and compare the surface structures of chromium-tin alloys fabricated by ion implantation and laser doping of chromium using the stable /sup 119/sn isotope