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

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 70keV N+ ion beam irradiation at a low dose of 1×1016 ions/cm2 while MWCNTs transformed into a-CNWs at a high dose of 7×1016 ions/cm2. At 1000K, the 70keV N+ ion beam irradiation of defective MWCNTs causes the curling of carbon clusters to an onion-like structure at a dose of 4×1016ions/cm2 and the formation of a low density onion-like structure at 7×1016 ions/cm2. Irradiation of the defective MWCNTs by 70keV Ar+ ion at 1000K and 7×1016 ions/cm2 leads to the formation of a high density onion-like structure. Irradiation of a-CNWs with 70keV H+ ion at 1000K gradually increases the fraction of material with a diamond structure with increasing dose from 1×1016 to 1×1017 ions/cm[2]. [New Carbon Materials 2013, 28(2): 81–87]