Evidence for substantial interaction between Gd ion and SWNT in (Gd@C82)n@SWNT peapods revealed by STM studies

A metallofullerene, Gd@C82, encapsulated in the inside space of single walled carbon nanotube (SWNT) has been identified as an STM image of a carbon cage and a Gd atom by a measurement of the tunnel currents onto the SWNT surface. This fact indicates that there is a substantial local interaction between the wall of SWNT and the Gd ions close to the wall. The origin of this interaction is not yet clear, but its existence has also been supported by the results of axially- and peripherally-resolved STS measurements around the Gd ion sites in the peapod.