High pressure synthesis of alkali metal intercalated C-60 polymers

Potassium and Rubidium doped A(x)C(60) (A = K, Rb; x = 1, 2, 3) were treate d under a pressure of 5 GPa at 573 K. After the treatment, the AC(60) sampl es (x = I) were transformed into orthorhombic 1D-polymers. The A(2)C(60) sa mples were transformed into a mixture of fee monomer phase and orthorhombic 1D-polymer. The fee A(3)C(60) Samples were unchanged even after the treatm ent. These changes are very different from those found in the high-pressure treatments of Li and Na doped C-60 fullerides, which transformed into the rhombohedral LiC60 and NaC60 2D-polymers, tetragonal LixC60 2D-polymer (x g reater than or equal to 2), and Na,C60 monomer phase (x greater than or equ al to 2). All of the polymers A(x)C(60) (X = 1; A = Li, Na, K, Rb) obtained by the high pressure treatment were semiconductors with the conductivities increasing in the order of Li<Na much less than K<Rb-forms.