We report our recent study of the electronic and geometric structure o
f Sc-encapsulated fullerenes (metallofullerenes) ScC74, Sc2C74, and Sc
2C84 adsorption on the Si(100)2 X 1 surface with field ion scanning tu
nneling microscopy. A comparison with the pristine C60 and C84 confirm
ed the assumption that the Sc atoms are encapsulated inside the carbon
cage. The charge transfer from the Sc atoms to the carbon cage is evi
denced. The presented results also show that these metallofullerenes d
o not prefer to form dimers or trimers.