▎ 摘　　要

Rutherford backscattering spectrometry (RBS) has been used to examine the inter-diffusion behaviour in Au thin films (similar to 30 nm) deposited on CVD grown monolayer Graphene on copper (Au/Gr/Cu) with reference to gold film deposited on copper (Au/Cu), under thermal annealing and ion beam irradiation processes. Graphene is acting as a diffusion barrier in Au/Gr/Cu upto 220 degrees C for the inter-diffusion of Au in Cu in thermal annealing process, while interdiffusion occurs below 200 degrees C in Au/Cu. In high temperature regime, bulk diffusion mechanism is dominant in Au/Cu system whereas grain boundary diffusion is dominant in Au/Gr/Cu system. The dominant grain boundary diffusion in Au/Gr/Cu indicates that grain boundary defects in graphene play a major role in inter-diffusion process. Upon 9 MeV Si6+ ion irradiation, there is no ion beam mixing upto 5 x 1015 ions/cm(2) and at the ion fluence of 3 x 10(16) ions/cm(2), ion beam mixing is observed in both Au/Cu and Au/Gr/Cu samples, with lower ion beam mixing rate and mixing efficiency for Au/Gr/Cu sample. This implies that graphene interlayer can prevent ion beam mixing to a certain extent due to its impermeable nature. The blue shift of Raman spectroscopy peaks G and 2D and the splitting of G-peak from graphene barrier layer signifies the compressive strain in Au deposited and thermally annealed Gr/Cu samples. Even though interlayer graphene can reduce the interdiffusion in Au/Cu system modestly, it becomes disordered with the formation of sp(3) carbon bonds with increase in annealing temperatures and ion fluences, thereby loosing its impermeable nature.