The study on the electrical resistivity of Cu/V multilayer films subjected to helium (He) ion irradiation

Highlights: • The resistivity change of the multilayer upon radiation was systematically studied. • The mechanisms for the resistivity change were proposed and discussed. • The interfaces during radiation play major roles in the resistivity change. • The study could be further used to gauge radiation damage of nuclear materials. Sputtering-deposited Cu/V multilayer films with the individual layer thickness varying from 2.5 nm to 100 nm were irradiated by 1 MeV helium (He) ion at the fluence of $6\times {10}^{16}\mathrm{ions}·{\mathrm{cm}}^{-2}$ at room temperature. The resistivity of Cu/V multilayer films after ion irradiation was evaluated as a function of individual layer thickness at 300 K and compared with their resistivity before ion irradiation. The results show that the resistivity change before and after ion irradiation is largely determined by the interface structure, grain boundary and radiation induced defects. A model amended based on the model used in describing the resistivity of as-deposited Cu/V multilayer films was proposed to describe the resistivity of ion irradiated Cu/V multilayer films by considering the point defects induced by ion irradiation, the effect of interface absorption on defects and the effect of interface microstructure in the multilayer films.