Nanostructure and formation mechanism of proto diamond shock-synthesized from graphite Original Research Article

A proto diamond with only tetragonally distorted diamond structure was found in a shock-compressed graphite particle. The nanostructure and electron structure were investigated by high resolution electron microscopy together with electron energy loss spectroscopy (EELS) and energy dispersive X-ray (EDX) analysis. The p-diamond consisted of nanosize grains and the individual grains were surrounded by numerous lattice defects. It was assumed that the lattice distortion of the p-diamond was attributed to an incomplete compression of the graphite lattice by weak shock compression. In addition, the phase transformation of graphite to p-diamond was inferred to occur by plastic shearing the graphite particles.