Electronic effects in scanning tunneling microscopy of dendritic, Cr-filled carbon nanotubes - art. no. 165432

We have used ultrahigh vacuum scanning tunneling microscopy (STM) to invest igate Cr-filled multiwalled carbon nanotubes. Dendritic and bamboo features were observed in this material. Anomalous contrast effects, resulting in e xtreme width-to-height ratios, are ascribed to tip effects as well as to in trinsic electronic properties of the filled tubes. In particular, we find t hat strong apparent height variations along the tube axis are sensitively d ependent on the imaging bias. These results suggest that Cr filling of carb on nanotubes results in strong electronic interactions between tube and fil ling materials.