  The kinetics of sorption and subsequent desorption of argon gas by a C60
powder has been investigated in the temperature interval 58-290 K. The
temperature dependence of the coefficients of Ar diffusion 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 range of the investigated temperatures, which corresponds to the
thermally activated diffusion of Ar atoms in fullerite. The glass transition in
fullerite induces an order-of-magnitude decrease in the activation energy of Ar
diffusion in fullerite. Most likely this is because new directions may appear
due to the glass transition in which the barriers separating the interstitial
voids in the C60 lattice are significantly lower
