Possible polymerisation at dislocations in C-60 crystals

It is known that under hydrostatic pressures of about 1 GPa the polymerisat ion of molecules in C-60 crystals occurs in a temperature range of about 40 0-600 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 C-6 0 molecules can be possible in the vicinity of dislocations in C-60 crystal s at elevated temperature. Here we report the results of stress-strain meas urements made on C-60 single crystals and the photoluminescence (PL) spectr a of plastically deformed samples. A hardening of samples with increase of the deformation temperature from 20 to 300 degreesC was observed together w ith a strong enhancement of some defect-related lines in PL spectra. We sup pose that the appearance of covalently bonded Csa molecules at dislocations is a possible reason for that.