The effect of glass transition in fullerite C60 on Ar impurity diffusion
A.V. Dolbin, V.B. Esel'son, V.G. Gavrilko, V.G. Manzhelii, N.A. Vinnikov, and R.M. Basnukaeva
B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Lenin Ave., Kharkov 61103, Ukraine
Received Octouber 24, 2012
The kinetics of sorption and subsequent desorption of argon gas by powdered C60 has been investigated in the temperature interval 58–290 K. The temperature dependence of the Ar diffusion coefficients in fullerite
has been obtained using the measured characteristic times of sorption. The diffusion coefficients of Ar decrease
monotonically with lowering temperature in the whole temperature range, what corresponds to the thermally activated diffusion of Ar atoms in fullerite.
The glass transition in fullerite induces an order-ofmagnitude decrease in the activation energy of Ar diffusion
in fullerite. This appears to be because of new directions appeared due to the glass transition in which
the barriers separating the interstitial voids in the C60
lattice are significantly lower.