Growth and Study of Superconducting C60 Compounds.

Abstract : A home made semi-automatic feeding plasma arc reactor was used for the mass production fullerenes. Large, high quality single crystals of C60 up to 3mm in length have been grown by both the open-end and sealed vapor transport techniques. Millimeter-sized superconducting single crystals of K3C60 were successfully produced by a sophisticated vacuum doping method. Magnetic and superconducting properties were obtained. Information on the field and temperature dependences of the critical current density J(sub c) and the H(c1) have been reported. New compounds of Yb(x) C60 with x=1-6 were synthesized using a liquid ammonia route at low T and in an inert atmosphere. It turns out that these compounds are amorphous and have a spin glass behavior at a temperature T<15K. Finally, new superconductors with T(sub c) of 134K were found in the system of Tl(1-x)HgBa2Ca2Cu3O(8+y). jg p1