Characterization of Ni2P(1010): Soft X-ray photoelectron spectroscopy study

Abstract

The composition and electronic structure of a Ni2P(1010) surface have been investigated with Auger electron spectroscopy (AES), low-energy electron diffraction (LEED), and photoelectron spectroscopy (PES) utilizing synchrotron radiation. As the Ni2P(1010) surface was sputtered by Ar+ ion (1 keV, 15 min), the concentration of P atoms in the surface region was reduced. As the surface was annealed at elevated temperatures, the concentration of P atoms was increased due to the segregation from the bulk. The segregation was found to proceed rapidly at 260-330°C. The surface before segregation of P atoms gave a diffused (1×1) LEED pattern, while the pattern changed to a c(2×4) pattern when the P atoms were segregated on the surface. The change in the surface electronic structure induced by the segregation of P atoms was investigated by PES. It was found that the spectral intensity of the valence band in the region of 0-2 eV was decreased when the P atoms were segregated to the surface, indicating that the 3d levels of surface Ni atoms were stabilized through the formation of bonds with the 3p levels of the segregated P atoms. © 2012 The Surface Science Society of Japan.