Modulation of the Local Density of States of Carbon Nanotubes by Encapsulation of Europium Nanowires As Observed by Scanning Tunneling Microscopy and Spectroscopy

Modulation of the local density of states of single-wall carbon nanotubes (SWCNTs) is induced by the encapsulation of europium nanowires (EuNWs). The observation of these modulated density of states using scanning tunneling microscopy/spectroscopy combined with density functional theory calculations is reported. The electronic modulation of SWCNTs by encapsulation of EuNWs is revealed as a Fermi level: shift, band gap reduction) and the emergence, of localized states in the gap. The present results show that the electronic interaction between EuNWs and SWCNTs is much stronger than that previously reported for nanomaterials encapsulated in SWCNTs.