Structural evolution and micromechanical property of amorphous carbon particles during arc plasma synthesis

By controlling the parameters of buffer gas in arc plasma, amorphous carbon (AC) particles with a tunable size distribution from submicron to nanoscale are prepared. The microstructural evolution of AC particles is systematically studied. For nano-sized particles, the quenching effect of buffer gas leads to a smaller mean size within a range of 17–52 nm, with a large amount of sub-nanosized voids and 1–2 nm graphene fragments. For submicron-sized particles, however, the mean size of AC increases from ∼195 to∼370 nm as the pressure of buffer gas increases, and less defects and larger graphene fragments are observed. In addition, the combined analyses of the density and in situ microcompression property also exhibits the structural and physical distinction for both AC particles.