Periodic, pearl chain-like nanostructure observed by scanning tunneling microscopy

A periodic, pearl chain-like nanostructure is observed in ultrahigh vacuum scanning tunneling microscopy (UHV-STM) of chromium filled carbon nanotubes. The structure displays one dimensional periodic morphology, with periodicity of ∼3.3 nm. Atomically resolved STM image of the pearl chain structure shows hexagonal periodicity. The origin of the pearl chain structure is discussed.