Photoemission studies ofTi3SiC2and nanocrystalline-TiC/amorphous-SiC nanocomposite thin films

Photoemission studies using synchrotron radiation have been performed on epitaxial ${\mathrm{Ti}}_3\mathrm{Si}{\mathrm{C}}_2\left(0001\right)$ 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, $\mathrm{Si}{\mathrm{O}}_x$ and $\mathrm{Ti}{\mathrm{O}}_x$. These oxides could be removed by in-situ annealing to $\sim 1000°\mathrm{C}$. For as-annealed ${\mathrm{Ti}}_3\mathrm{Si}{\mathrm{C}}_2\left(0001\right)$, surface Si was observed and interpreted as originating from decomposition of ${\mathrm{Ti}}_3\mathrm{Si}{\mathrm{C}}_2$ through Si out-diffusion. For $\mathrm{nc}\text{−}\mathrm{Ti}\mathrm{C}∕a\text{−}\mathrm{Si}\mathrm{C}$ annealed in situ to $\sim 1000°\mathrm{C}$, 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 $a\text{−}\mathrm{Si}\mathrm{C}$ compound or from grain boundaries.