Investigation of ytterbium fulleride compounds

We have synthesized the ytterbium fulleride compounds YbxC60 (x=1–6) at a range of lower temperature (530 °C–570 °C). Except for the nominal composition Yb3C60 compound, which has been reported in the references, we also obtained a new phase Yb6C60, whose structure is orthorhombic with space group P21212 and unit cell parameters a=21.28 A, b=20.13 A and c=15.89 A. The YbxC60 compounds are sensitive to oxygen, the samples exposed in air convert to an amorphous phase and Yb2O3 compound.