Site-specific surface atom valence band structure via X-ray standing wave excited photoemission

TL;DR

This paper introduces a novel X-ray standing wave photoemission method to measure site-specific valence band structures of surface atoms, validated on Pt/SrTiO3, combining experimental data with density functional theory calculations.

Contribution

It presents a new technique for analyzing the contribution of specific atomic sites to the valence band structure using XSW excited photoemission.

Findings

Pt exhibits fcc-like cube-on-cube epitaxy with substrate

XSW measurements align with density functional theory calculations

Method enables site-specific valence electron analysis

Abstract

X-ray standing wave (XSW) excited photoelectron emission was used to measure the site-specific valence band (VB) for 1/2 monolayer (ML) Pt grown on a SrTiO3 (001) surface. The XSW induced modulations in the core level (CL) and VB photoemission from the surface and substrate atoms were monitored for three hkl substrate Bragg reflections. The XSW CL analysis shows the Pt to have an fcc-like cube-on-cube epitaxy with the substrate. The XSW VB information compares well to a density functional theory calculated projected density of states from the surface and substrate atoms. Overall, this work represents a novel method for determining the contribution to the density of states by valence electrons from specific atomic surface sites.