SR-Excited Angle-Resolved-Ultraviolet-Photoelectron-Spectroscopy Study of One-Dimensional Electronic State on Ni(332) Stepped Surface

Abstract

We have investigated the surface electronic structure of stepped Ni(332)[=6(111)×(111)] in the expectation of observing one‐dimensional surface state by angle‐resolved ultraviolet photoelectron spectroscopy using synchrotron radiation(SR‐ARUPS). In SR‐ARUPS spectra, we observed two surface‐sensitive peaks at ∼0.5 and ∼0.1 eV below Fermi level EF revealed by O2 adsorption. The former peak disperses downwards away from EF parallel and perpendicular to the steps, which can be attributed to the (111) terrace‐derived two‐dimensional surface state. Though the latter peak disperses upwards parallel to the steps, on the other hand, it has almost no dispersion in the perpendicular direction. This flat dispersion is the clear evidence that the peak just below EF stems from an electronic state localized at the steps. Considering the flat and upwards dispersions perpendicular and parallel to the steps, this step‐localized state is concluded to be one‐dimensional electronic state.