Effect of low-temperature compression on the parameters of the phase transition at 250-260 K in C-60 single crystals

A thermodynamic transition in C-60 crystals, subjected beforehand to uniaxi al compression at various temperatures and to thermal action, was investiga ted by differential scanning calorimetry. It was established that compressi on of the crystal at temperatures below the phase transition has a much sma ller effect on the transition itself than a similar or even much weaker act ion at a temperature above the phase transition. A "quenching" effect was a lso found. This effect is probably due to the orientational order of indivi dual fullerene molecules. A correlation was established between the magnitu de of the effect and the preliminary deformation of C-60 crystals. (C) 1999 American Institute of Physics. [S1063-7834(99)03503-0].