Synthesis and superconductivity of organometallic fullerides M_(3–n)(NR₄)_(n)C₆₀, where M = K, Rb; R = H, D, Me, Et, Bu; n = 1, 2, 3

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. (author)