H+, N+, and Ar+ ion irradiation induced structure changes of carbon nanostructures

Abstract

The effects of H + , N + , and Ar + ion irradiation on structural changes in multi-walled carbon nanotubes (MWCNTs) and amorphous carbon nanowires (a-CNWs) were investigated at room and elevated temperatures with different irradiation doses. It is found that at room temperature, defects were introduced in MWCNTs under 70 keV N + ion beam irradiation at a low dose of 1 × 10 16 ions/cm 2 while MWCNTs transformed into a-CNWs at a high dose of 7 × 10 16 ions/cm 2 . At 1000 K, the 70 keV N + ion beam irradiation of defective MWCNTs causes the curling of carbon clusters to an onion-like structure at a dose of 4 × 10 16 ions/cm 2 and the formation of a low density onion-like structure at 7 × 10 16 ions/cm 2 . Irradiation of the defective MWCNTs by 70 keV Ar + ion at 1000 K and 7 × 10 16 ions/cm 2 leads to the formation of a high density onion-like structure. Irradiation of a-CNWs with 70 keV H + ion at 1000 K gradually increases the fraction of material with a diamond structure with increasing dose from 1 × 10 16 to 1 × 10 17 ions/cm[2]. [New Carbon Materials 2013, 28(2): 81–87]