Influence of cyclic temperature variation near the first order phase transition on hypo molecular structure of solid C60

Methods of neutron diffraction analysis are used to reveal variation in a hypomolecular structure of a C60 solid phase under thermal cycling within the range of the first order transition temperature (Tc = 260 K). The subgrain size (D ∼ 30-50 nm) inside crystals is dose to a correlation radius of inhomogeneities Rc at grain boundaries. Inhomogeneities with rc ∼ 3-4 nm (structure with a scale of ∼ 10 nm) are found at the surface as well. Cyclic cooling below Tc decreases a large defect concentration by ∼ 6%, is destructive to the structure with a scale of ∼ 10 nm and promotes the formation of more smooth surface