Production and Discovery of Fullerites: New Forms of Crystalline Carbon [and Discussion]

Small carbon grains are assumed to be the carrier of the prominent interstellar ultra violet absorption at 217 nm. To investigate this hypothesis, we produced small carbon particles by evaporating graphite in an inert quenching gas atmosphere, collected the grains on substrates, and measured their optical spectra. In the course of this work - which in the decisive final phase was carried out with the help of K. Fostiropoulos and L. D. Lamb - we showed that the smoke samples contained substantial quantities of C$_{60}$. The fullerene C$_{60}$ (with small admixtures of C$_{70}$) was successfully separated from the sooty particles and, for the first time, characterized as a solid. We suggested the name `fullerite' for this new form of crystalline carbon.