Possible Polymerisation at Dislocations in C60 Crystals

It is known that under hydrostatic pressures of about 1 GPa the polymerisation of molecules in C60 crystals occurs in a temperature range of about 400–600 K. The same strain of a lattice can be achieved in the vicinity of a dislocation core. Therefore, one can suppose that the polymerisation of C60 molecules can be possible in the vicinity of dislocations in C60 crystals at elevated temperature. Here we report the results of stress–strain measurements made on C60 single crystals and the photoluminescence (PL) spectra of plastically deformed samples. A hardening of samples with increase of the deformation temperature from 20 to 300 °C was observed together with a strong enhancement of some defect-related lines in PL spectra. We suppose that the appearance of covalently bonded C60 molecules at dislocations is a possible reason for that.