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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 °C or Y alloy — Bi, Sn, Pb, In, Cd, Tl with Tm = 41.5 °C. The synthesis of heterofullerides 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. [ABSTRACT FROM AUTHOR]

We present experimental data on the synthesis and investigation of the superconducting and structural properties of organometallic fullerides M(3−n)(NR4)(n)C60, where M = K, Rb; R = hydrogen H, deuterium D, methyl Me, ethyl Et, butyl Bu; n = 1, 2, 3, synthesized by exchange reactions of homofullerides of alkali metals of composition K3C60 and Rb3C60 with ammonium halides in the medium of absolute toluene or tetrahydrofuran (THF) at temperatures from 23°C to 110°C. We have studied also superconductivity in Rb2NH4C60 and Rb2ND4C60 samples with replacement of hydrogen for deuterium in ammonium, as well as in K2NH4C60 and K2ND4C60. The superconducting transition temperature did not change with replacement H by D within the measurement accuracy. [ABSTRACT FROM AUTHOR]