STRONTIUM DOPED FULLERITE COMPOUNDS

We report synthesis, structures and properties of strontium intercalated fullerite, SrxC60 compounds. This is identified as the only fulleride system where fcc and bcc phases compete in the same compositional range. In the vicinity of x=3, a bcc A15 phase coexists with a fcc phase with lattice constants 11.140 and 14.144 angstrom, respectively. For Sr6C60, an Im3BAR bcc phase with a0=10.975 Angstrom is observed. This phase becomes superconducting at T=4 K. These structural and electronic properties, being intermediate to grossly different calcium and barium intercalated fullerides, provide a unifying picture of all alkaline-earth intercalated fullerides.