Effects of impurities on Tamm-like lanthanide-metal surface states

TL;DR

This study investigates how residual-gas impurities affect the local electronic structure of Dy(0001) surface states, revealing impurity scattering effects and a metastable adsorbate-induced state using STM/STS at low temperature.

Contribution

It provides detailed spatial mapping of impurity effects on Tamm-like lanthanide-metal surface states, highlighting their high lateral localization and impurity-induced states.

Findings

Impurities cause a strong reduction in surface state intensity near adsorbates.

Impurities induce a metastable adsorbate-induced electronic state.

The majority component of the surface state is significantly affected by impurity scattering.

Abstract

The effects of isolated residual-gas adsorbates on the local electronic structure of the Dy(0001) surface were spatially mapped by scanning tunneling microscopy and spectroscopy at 12 K. Less than 15 A away from an adsorbate, a strong reduction of the intensity and a significant increase of the width of the majority component of the surface state due to impurity scattering were observed, with essentially no change of the minority component; this reflects a high lateral localization of the Tamm-like surface state. Furthermore, an adsorbate-induced state was found that behaves metastable.