Pressure studies on fullerene peapods

We carried out pressure‐dependent transmission measurements on single‐walled carbon nanotubes (SWCNTs) filled with C60 molecules, so‐called C60 peapods, in the near‐infrared and visible frequency range, where the optical transitions between the Van Hove singularities of the carbon nanotubes are excited. The pressure‐induced shifts of the optical transitions exhibit an anomaly associated with the deformation of the carbon nanotubes. The results are compared with those for empty SWCNTs. Furthermore, the importance of the pressure transmitting medium used in the measurements is discussed.