Ion-induced electron emission of glassy carbons

Abstract

The temperature dependence (−200°C<T⩽350°C) of ion-induced electron emission yield, γ, for glassy carbons with different heat treatment (from 850 to 2500°C) under high-dose (1018–1019ion/cm2) 30keV Ar+ and N2+ normal incidence ion bombardment has been measured. A step-like increase in the yield at certain annealing temperature Ta has been detected only for relatively “high-temperature” glassy carbons, when RHEED has shown diffraction patterns corresponding to a high degree RT-irradiation-caused disorder. It is analogous to that for the graphitized carbon-based materials, which is due to an increase in electron path length during the radiation damage annealing. For the “low-temperature” glassy carbons only a slow monotonic increase in γ with the irradiation temperature has been observed. The obtained results are discussed in terms of both accumulation and annealing of the radiation damage, the presence of some fullerene-related structures in the glassy carbons and their role in the ion-induced electron emission.