Konyashin, I., V. Khvostov, et al. (2005). "A new hard allotropic form of carbon: Dream or reality?" Int. J. Refract. Met. Hard Mater. 24: 17-23.

An unusual phase of carbon with fcc. crystal structure, the lattice const. of which is close to that of diamond, was reported before in a no. of publications. In all the published works, the existence of fcc. carbon could not be unambiguously established, as only insignificant amts. of fcc. carbon in the mixt. with other carbon modifications were obtained so far. The present work provides for the first time clear evidence for the existence of the carbon modification with the fcc. crystal structure. Thin films consisting exceptionally of fcc. carbon were obtained by various methods, namely by hot-filament CVD, plasma-assisted CVD and treatment of the diamond surface in hydrogen plasmas. Results of electron diffraction, Raman spectroscopy, AES, XPS, EELS, and HRTEM of the films consisting of fcc. carbon clearly indicate its unique crystal and electronic structure. The microhardness of the films of fcc. carbon was equal to HV0.01 = 250 which is quite different from the hardness of all the known carbon modifications.