  Thermoelastic phenomena associated with orientational phase transition in
solid C60 are considered. Coupling of the order parameter with elastic strain
is analyzed in the Landau theory of phase transitions. Wide range of possible
coexistence of the FCC phase with SC one in C60 has been found from 260 K down
to critical temperature 160 K of the instability of high-symmetry phase. The
specific heat, thermal expansion coefficient and isothermal compressibility for
low-symmetry phase are calculated as function of temperature and pressure in an
agreement with reported data. Applicability of the Landau theory to ordering
transition in fullerenes is discussed.
