Small-inelastic-strain rate spectrum of C-60 single crystals near the phase transition at 250-260 K

The temperature spectrum of small-inelastic-strain rates in a vapor-phase-g rown C-60 single crystal has been measured within the 200-290 K interval wi th a high-precision strain-rate meter based on a laser interferometer. The spectrum exhibits a strong peak in the region of the phase transition at 25 0-260 K and a slight strain acceleration at similar to 240 K, which correla tes well with the calorimetric curve. The first maximum is associated with strain that developes more easily in an fcc than in a primitive cubic latti ce, and the second, to the effect on the strain rate of annealing of the de fects created with fast crystal heating. (C) 1999 American Institute of Phy sics. [S1063-7834(99)04006-X].