Giant Fullerene-Like Hollow Spheres Generated from Shock-Compressed C₆₀ Fullerene by an Impact of Metal Flyer

Abstract

C₆₀ fullerene powder set into a stainless capsule was shock-compressed by using a powder gun. The capsule was compressed to 57 GPa by a W flyer with a velocity of 1.72 km/s. The recovered sample was investigated by scanning electron microscopy and Raman spectroscopy. We found the generation of fullerene-like carbon hollow spheres up to several μm in diameter on an internal hollow surface of the recovered sample. The spheres are significantly larger than fullerenes reported so far and are revealed to be in a highly graphitized state by Raman spectroscopy. Also we found exfoliation of the internal hollow surface at intervals. The formation mechanism of the carbon hollow spheres through a liquid phase is proposed.