Low-dimensional NbO structures on the Nb(110) surface: scanning tunneling microscopy, electron spectroscopy and diffraction

TL;DR

This study uses microscopy and spectroscopy techniques to analyze low-dimensional NbO structures on Nb(110), revealing a quasi-ordered superstructure with surface-adsorbed oxygen and a NbO composition.

Contribution

It provides a detailed characterization and a proposed structural model of NbO layers on Nb(110), combining multiple analytical methods.

Findings

Niobium atoms form a 2D superstructure on Nb(110)

The oxide layer is identified as NbO with surface chemisorbed oxygen

A structural model of NbO on Nb(110) is proposed

Abstract

X-ray photoelectron spectroscopy and diffraction (XPS, XPD) and scanning tunneling microscopy (STM) have been used for study of NbOx-structures on the Nb(110) surface. It is shown that niobium atoms are ordered to form a two-dimensional superstructure with equidistant spacing between the chains of niobium atoms. Chemical shifts of Nb3d- and O1s-levels demonstrate that the oxide layer corresponds to niobium monoxide NbO and the most part of oxygen in chemisorbed state is localized on the surface. A model of quasi-ordered structure of NbO on the Nb(110) surface is proposed.