Emission of the ferrocene molecules encapsulated in single-walled carbon nanotubes by X-ray irradiation

Abstract We studied X-ray irradiation effects of the single-walled carbon nanotubes (SWNTs) encapsulating ferrocene (Cp 2 Fe) molecules. Cp 2 Fe was encapsulated into SWNT by thermal treatment at 200 °C for 12 h in a vacuum-sealed glass tube. Raman scattering spectroscopy revealed that the SWNT after the encapsulation showed a high-frequency shift of the radial breathing modes (RBMs). The similar high-frequency shift was reported for the Cp 2 Fe encapsulated SWNT, and therefore we concluded that the Cp 2 Fe molecules were successfully encapsulated in SWNT. The exposure of the encapsulated SWNT with 1.25 keV X-ray gave the enhancement of the defect-related band, D band, but not shift the RBM peak in the Raman scattering spectra. The energy dispersive X-ray spectroscopy revealed that the X-ray irradiation reduced the atomic concentration of Fe from 0.24% to 0.15%. The result suggests that the X-ray irradiation leads to the emission of Cp 2 Fe molecules.