Concentric-shell fullerenes and diamond particles: A molecular-dynamics study

Concentric-shell fullerenes are generated from diamond nanoparticles of 1.2 nm to 1.4 nm diameter by means of molecular dynamics simulations based on approximate Kohn-Sham equations. The diamond-to-concentric-shell fullerene transformation observed at temperatures from 1400 K to 2800 K starts at the surface of the diamond particle. Subsequently, the core of the particle ge ts disordered and the information about the initial atomic structure become s lost. The final structure consists of two concentric graphitic shells. Th e intershell spacing of the generated concentric-shell fullerenes is distin ctly below the interlayer distance of graphite. It is demonstrated that sp( 3)-like cross links appear between the shells. Simulated irradiation accele rates the transformation but reduces the number of cross links. [S0163-1829 (99)14039-6].