Surface crystallography of bulk-grownCoSi2(111) by x-ray photoelectron diffraction

The surface termination of the (111) face of a ${\mathrm{CoSi}}_2$ bulk crystal is determined through a comparison between experimental results from x-ray photoelectron diffraction and theoretical multiple-scattering calculations for different surface models. It is found that the bulk crystal is terminated by only one Si layer as opposed to epitaxially grown ${\mathrm{CoSi}}_2$ films on Si(111) which can exhibit surfaces with one or more Si layers, depending on the epitaxial growth conditions. Confirmation of the results is found through analysis of data from photoelectron diffraction at low photon energy (∼120 eV).