Modulating Grain Size of Nanostructured Cu Films by Magnetron Sputtering

Grain size is a critical factor determining materials properties but is challenging to be modulated in nanoscale. Here, we found the grain size can be enhanced from ~23 nm to ~557 nm for Cu but slightly from ~30 nm to ~145 nm for Cu 96 W 4 with the substrate temperature from 298 to 773 K using magnetron sputtering. The smaller grain size of Cu 96 W 4 compared to that of Cu originates from the lower diffusion coefficient of solid-solution W and W particles, depending on the substrate temperature and W content. This finding provides guidance for modulating the grain size of high-performance nanostructured materials