Valence-Band UPS, 6$p$ Core-Level XPS Photoemission Spectroscopy, and Low-Energy Electron Diffraction of a Uranium (001) Single Crystal

TL;DR

This study combines UPS, XPS, and LEED techniques to analyze a uranium (001) single crystal, revealing detailed electronic structure and surface order consistent with theoretical calculations.

Contribution

It provides comprehensive experimental characterization of uranium's surface and electronic properties, validated by first-principles calculations.

Findings

Good agreement between experimental spectra and GGA calculations

Identification of a well-ordered orthorhombic surface structure

Confirmation of bulk electronic properties at the surface

Abstract

Valence-band ultraviolet photoemission spectroscopy (UPS) at 173K and 6p core-level X-ray photoemission spectroscopy (XPS) at room temperature were performed on a high quality uranium single crystal. Significant agreement is found with first-principles electronic band-structure calculations, using a generalized gradient approximation (GGA). In addition, using Low Energy Electron Diffraction (LEED) for the (001) surface, we find a well-ordered orthorhombic crystallographic structure representative of the bulk material.