Europhys. Lett, 48 (6), pp. 662-666 (1999)
The non-exponential relaxation of the C60 crystal around glass transition temperature
F. Yan 1, Y. N. Wang 1 and J. S. Liu 2
1 National Laboratory of Solid State Microstructures, Institute for Solid State Physics
Center for Advanced Studies in Science and Technology of Microstructures
Department of Physics, Nanjing University - Nanjing 210093, PRC
2 Center of Advanced Studies, Tsinghua University - Beijing 100084, PRC
(received 28 April 1999; accepted in final form 11 October 1999)
PACS. 64.70Pf - Glass transitions.
PACS. 61.48 - Fullerenes and fullerene-related materials.
PACS. 02.50Ng - Distribution theory and Monte Carlo studies.
A model of the energy barrier of a molecule between two orientational states in the crystal, which depends on the neighboring molecules, is first proposed. Based on this model, the orientational relaxation of molecules around 90 K was simulated with the Monte Carlo method. The simulation results show that the relaxation is slightly non-exponential and can fit the Kohlrausch-Williams-Watts (KWW) function with the non-exponential factor , which is equal to the experimental data that has not been explained before.
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