Terrestrial development of the experiments on the fullerite C$_{60}$ crystal growth in microgravity

Microgravity creates favorable conditions to reduce dislocations and grain boundaries density in growing crystals due to absence of close contact with the ampoule walls and absence of plastic deformation of the crystal under its own weight. For improvement of the fullerite C$_{60}$ crystal growth technology before the scheduled space experiments on the ISS the growing of the high purity grade fullerite C$_{60}$ crystals with the sufficiently high structural perfection were carried out on the Earth from the C$_{60}$ vapor in sealed quartz ampoules (pre-evacuated to the pressure of 10$^{-3}$ Pa) at temperatures in the evaporation zone ranging from 560 – 610$^\circ$ C with a temperature gradient between the evaporation and deposition zones of 3 – 10 K/cm within 72 h. The grown single crystals had a size of $\sim$ 5 $\times$ 5 $\times$ 5 mm and habitus corresponding to the fcc lattice. IR spectroscopy shows the high purity fullerite C$_{60}$.