Fullerides: Heterometallic superconductors with composition M2M′C60 (M = K, Rb; M′ = Yb, Lu, Sc)

Article abstract of DOI:10.1007/s11172-005-0018-9

One- or two-step reactions of potassium and rubidium fullerides with composition M_k C₆₀ (M = K, Rb; k = 3-6) and K ₆C₆₀ + m K mixtures (m = 1, 3) with anhydrous salts M′Cl₃ (M′ = La, Pr, Nd, Sm, Gd, Tb, Yb, Lu, Y, Sc) and YbI2 in a toluene-THF medium afforded heterometallic fullerides M3- _n M′_n C₆₀ (n = 1-3). Among these compounds, substituted fullerides with composition M₂M′C₆₀ (M′ = Yb, Lu, Sc) display superconducting properties with critical temperatures of 14-20 K.