Temperature Dependence of the Coherent Radial Breathing Mode Oscillations in Single Walled Carbon Nanotubes

We report on temperature dependence of the radial breathing mode(RBM) frequency and its decay time in single walled carbon nanotubes (SWCNTs), which were studied by the femtosecond pump and probe technique. With increasing temperature, we found out that the RBM frequency and phonon decay time shows on abnormal dramatic change around 70degC for a certain type of carbon nanotubes, which may be originated from the surfactant effect.