Angle-Resolved and Resonant Photoelectron Spectroscopy Study of Ni₂P (10−10) Single-Crystal Surface

Abstract

The electronic structure of Ni₂P (10−10) has been investigated by photoemission spectroscopy (PES) utilizing synchrotron radiation. The surface which was cleaned by Ar⁺ ion sputtering (3 kV, 15 min) and annealing (400^oC) gave a c (2×4) low-energy electron diffraction pattern. In the PES spectra measured for this surface, a Ni 3d-P 3p hybrid band (main band) and a satellite were observed at 0—4 eV and at 8 eV, respectively. Resonant PES (RPES) study showed that the satellite is associated with the photoemission process leading to a two-hole bound final state. The angle-resolved PES measurements showed that there were at least two surface states ; one was observed at about 0.4 eV around the Γ⁻ point and the other was observed at about 0.6 eV along the boundary of the surface Brillouin zone along the [0001] direction. The results of RPES measurements suggested that the latter state should have little contribution of the Ni 3d component.