Angle-resolved photoemission study ofAuGa2andAuIn2intermetallic compounds

The (001) surfaces of ${\mathrm{AuGa}}_2$ and ${\mathrm{AuIn}}_2$ intermetallic compounds were studied with use of synchrotron-radiation-excited angle-resolved photoemission. Spectra collected for photoelectron emission normal to the sample surfaces were used to map the E versus k→ dispersion relation of both compounds along the Δ symmetry line of the bulk Brillouin zone. The results show that the Au 5d bands of each compound are relatively flat, but the splittings of the bands at point Γ are nearly the same as for elemental Au. A surface state was also observed on each surface in a band-gap region about 6 eV below the Fermi levels of the two compounds.