Surface erosion of BaF2 thin films under SHI irradiation: Angular distribution and role of different substrates

Abstract In the present report, the surface erosion of the thin films of barium fluoride (BaF2) deposited on different substrates (Glass, Silicon, and Aluminum) using the electron beam evaporation method, has been investigated under swift heavy ions irradiation employing experimental and theoretical aspects. The experiments have been carried out at room temperature using normally incident 100 MeV Au+28 ions. Rutherford backscattering spectrometry has been employed to estimate the sputtering yield and angular distribution of sputtering yield has been obtained using the unique catcher technique approach. The variation of sputtering yield at different angles shows an isotropic distribution superimposed with enhanced sputtering at surface normal. The sputtering studies in the thin films on different substrates show that the maximum sputtering takes place for glass (insulator) substrate while minimum sputtering occurs for the aluminum (metal) substrate. Simulations based on the inelastic thermal spike model have been performed to compare the observed experimental findings. The temperature spike generated in Al will smear out more efficiently and quickly because of its high thermal conductivity as compared to Si and glass substrates resulting in less contribution to the temperature spike generated in the film and thus causing lower sputtering yield for Al substrate.