Mechanical tests of C-60/C-70 Single crystals allow one to assign them
to the category of soft and fragile materials. Their mechanical prope
rties are comparable with those of graphite but, in contrast, they are
isotropic. The dependence of C-60/C-70 microhardness on the temperatu
re in the range 77-570 K and on the influence of solvent residues has
been examined. Preliminary data on microhardness of pure C-60 and C-70
have been obtained.