Modification of the Nanoglobular Structure of Glassy Carbon by Heat Treatment and Ion Irradiation

Resumo

The results of a comparative experimental study of the structure and morphology of high-temperature glassy carbon of brand SU-2500 after high-fluence (10¹⁸ cm^–2 and higher) irradiation with 30-keV Ar⁺ ions in the temperature range of 60–600°С and glassy carbon samples after treatment at temperatures of 850, 1300, 2000, and 2500°С are reported and discussed. The Raman spectra of irradiated glassy carbon SU-2500 show the amorphous state of the surface layer after irradiation at temperatures below that of dynamic annealing of radiation damage, which is determined from the temperature dependence of the ion-induced electron emission yield, a graphite-like state after irradiation at temperatures of 150–250°С, and a structure typical of glassy carbon samples treated at elevated temperatures after irradiation at temperatures in the range of 250 < T ≤ 600°С. Ion irradiation under conditions of the dynamic annealing of radiation damage leads to a сellular topography, i.e., nanowalls connected by nodes. The sizes of the structure cells are about 150 and 300 nm after irradiation at temperatures of 250 and 600°С, respectively.