Angle-resolved photoemission study ofAuGa2andAuIn2intermetallic

Abstract

The (001) surfaces of AuGa2 and AuInz 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 6 symmetry line of the bulk Brillouin zone. The results show that the Au Sd bands of each compound are relatively flat, but the splittings of the bands at point I 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.

Electronic and Optical Properties of AuAl2 and PtAl2

“…On the other hand, the band which we have obtained immediately above the r; band near the Fermi energy is purely of s-p character and thus confirms the prediction of [9]. Recent angle resolved photoemission studies of intermetallics by Nelson et al [23] have also supported our band positions. In their results they obtained a peak near the Fermi energy which corresponds to photoemission from an s-p band that rises steeply between l and X, crossing the Fermi level before reaching r, which asserts our band positions very well.…”

“…The next two small structures near the Fermi energy correspond to the closely lying s-p bands, which rise sharply and intersect the Fermi level in the T-X and T-K region. These two features are well confirmed by the angle resolved photoemission study of Au intermetallics [23]. The structure at the Fermi energy is due to the flat portion of the degenerate band Tls-Lj around L.…”

Optical properties and electronic structures of d- and f-electron metals and alloys, Ag-In, Ni-Cu, AuGa2, PtGa2, [beta]'-NiAl, [beta]'-CoAl, CeSn3, and LaSn3

“…They are used only to try to separate i into two parts. of AuGa2 [108]. Also, the measured energy gap between and the lower from the above measurement is 1.6 eV while our calculation gives 1.1 eV.…”

Phonon dynamics of binary intermetallic compounds AuX2 (X=In, Al)

“…The binary intermetallic compounds AuX 2 (X = In, Al) have a cubic fluorite (CaF 2 ) structure [18]. The lattice is constructed from three interpenetrating fcc sublattices.…”

“…Low temperature studies in these compounds show that many of them become superconducting with low Tc and are employed in reference devices for precision thermometry below 1 K [7]. The electronic structure of AuX 2 intermetallics has been investigated by both computationally [8] and experimentally [9][10][11][12][13]18]. X-ray absorption near edge spectroscopy measurements on AuAl 2 shows that there is a strong chemical bonding with a depletion of the effective 5d orbital count [14].…”