Superconductivity of potassium and rubidium heterofullerides modified with low-melting alloys
N. S. Ezhikov, B. M. Bulychev, R. A. Lunin, and V. A. Kulbachinskii
Lomonosov Moscow State University, Low Temperature Physics and Superconductivity Department GSP-1, Moscow 119991, Russia
Received September 29, 2020, published online November 24, 2020
The paper provides experimental data on the synthesis and study of the superconducting properties of potassium and rubidium heterofullerides modified by Wood’s alloy — Sn, Pb, Bi, Cd (hereinafter W) with a melting temperature Tm = 61.5 °Сor Y alloy — Bi, Sn, Pb, In, Cd, Tl with Тm = 41.5 °С. The synthesis of hetero-fullerides was carried out by the interaction of fullerides of the composition K2C60 and Rb2C60, which do not have superconducting properties, with one of the alloys W or Y in an organic solvent — toluene at 100–110 °C. The samples obtained in this case showed superconducting properties with Tc = 8 K for K2YC60 and Rb2WC60 and 16 K for K2WC60.
Key words: heterofullerides, Wood’s alloy, superconducting properties.