Grain boundary self-diffusion in Fe films with a stable nanostructure

摘要

Grain boundary self-diffusion in Type-C regime was investigated in nano-crystalline bcc iron at low temperatures between 100 and 250 °C using neutron reflectometry in combination with [natFe(7 nm)/57Fe(3 nm)]10 isotope multilayers. The method allows to determine diffusivities in a stable nanostructure without concurrent grain growth. An activation enthalpy of diffusion of (0.9 ± 0.3) eV is found, comparable to the value of coarse-grained Fe.