Electronic sputtering of SiC and KBr by high energy ions

We have measured electronic sputtering yields of SiC and KBr by high-energy ions (198 MeV Xe, 99 MeV Xe, 89 MeV Ni, 60 MeV Ar and 55 MeV Cl ions with the equilibrium charge). Employing the carbon-foil collector method, sputtered atoms in the C-foil are analyzed by Rutherford backscattering spectrometry (RBS) and the sputtering yields have been evaluated. It appears that the sputtering yields Y follow the power-law of the electronic stopping power (Se): Y=(1.86Se)1.53 and Y=(0.77Se)3.0 for SiC and KBr, respectively (Se in keV/nm). The representative sputtering yield at Se = 10 keV/nm is evaluated to be 87.6 and 457 for SiC (bandgap Eg = 2.86 eV) and KBr (Eg = 7.4 eV) and it is revealed that these can be explained within the bandgap scheme. Lattice disordering by ion impact has been also measured by X-ray diffraction (XRD) and Se dependence of the XRD intensity degradation is compared with that of electronic sputtering.