Photoemission studies of Ti_3SiC_2 and nanocrystalline-TiC/amorphous-SiC nanocomposite thin films

摘要

Photoemission studies using synchrotron radiation have been performed on epitaxial Ti_3SiC_2(0001) and compound nanocrystalline (nc-)TiC/amorphous (a-)SiC thin films deposited by magnetron sputtering. As-introduced samples were found to be covered by surface oxides, SiO_x and TiO_x. These oxides could be removed by in-situ annealing to ～1000℃. For as-annealed Ti_3SiC_2(0001), surface Si was observed and interpreted as originating from decomposition of Ti_3SiC_2 through Si out-diffusion. For nc-TiC/a-SiC annealed in situ to ～1000℃, the surface instead exhibited a dominant contribution from graphitic carbon, also with the presence of Si, due to C and Si out-diffusion from the a-SiC compound or from grain boundaries.