Three Components Organic Superconductors: Intercalation of KH into C60

We have prepared (KH)3C60 as an initial composition by direct reaction of potassium hydride (KH) to C60. (KH)3C60 had higher Tc(19.5 K) and larger lattice constant (14.351 ?) compared with K3C60 prepared by doping of potassium metal. The expanded lattice constant is suggestive of the intercalation of hydrogen. The evidence of the inclusion of hydrogen was given by mass-analyzed thermal desorption experiment. We have also prepared (NaH)4-x(KH)xC60 to study the substitutional effect of KH to (NaH)4C60. It was found that the superconducting phase is stabilized by substitution of only a few percent KH as seen in (NaH)3.9(KH)0.1C60.