Dislocation mobility in C$_{60}$ fullerite crystals

The dependences of the path of leading dislocations in indentation rosette rays on the load, the loading time, and the indentation temperature in the range 260 $\lt T\le$ 373 K were studied for C$_{60}$ fullerite crystals. The dislocation mobility parameters are estimated: the exponent $m$ characterizing the stress dependence of the dislocation velocity depends on the structural perfection of the crystal and ranges from 2.3 to 24.5, the activation energy for dislocation motion $\Delta H_0\simeq$ (0.4–0.5) eV, and the velocity of leading dislocations in indentation rosette rays $v_l\simeq$ 10$^{-5}$–10$^{-4}$ cm/s. The data from micro-and macromechanical experiments are shown to agree with each other. The dislocation mobility is assumed to be controlled by the dislocation interaction with local barriers.