In situ Fourier-transform infrared study of electron-irradiation-induced reaction in a C-60 film

The reaction between C-60 molecules in a 3-keV electron-irradiated C-60 thi n film has been studied using in situ Fourier-transform infrared (FTIR) spe ctroscopy and ex situ laser-desorption FT-mass spectrometry (LD-FTMS). The results of FTIR and LD-FTMS measurements indicate that coalesced C-120 spec ies were formed as a main product in the electron-beam (EB)-irradiated film . We studied the kinetics of the reaction by examining the decrease in the amount of C-60 molecules as a function of irradiation time and found that t he reaction rate exhibits a linear dependence on the reactant concentration and a third-power dependence on the electron dose rate.