Superconductivity in fullerene compounds

Abstract

In this contribution some superconducting properties of fullerene superconductors are summarized. The dependence of the transition temperature Tc on the internal C60 spacing, on the external pressure and on the magnetic field is related to the density of states at the Fermi level N(EF). From low field magnetization measurements the lower critical fields of Rb3C60 and K2CsC60 are derived and the penetration depths are calculated. Analysing the hysterical magnetization loops in fields up to 9 T in the framework of the Bean model yields estimations of the critical current densities.

Superconducting selenides intercalated with organic molecules: synthesis, crystal structure, electric and magnetic properties, superconducting properties, and phase separation in iron based-chalcogenides and hybrid organic-inorganic superconductors

“…By this process superconducting fullerides A 3 C 60 (A = K, Rb, Cs) were synthesized, with transition temperatures as high as 29.5 K for Rb 3 C 60 at ambient pressure. The highest transition temperature, T c = 40 K, was found under pressure for Cs 3 C 60 , which is not superconducting at ambient conditions [64,65]. Superconducting fullerides crystallize under normal pressure in a face centered regular structure with alkali metal ions residing in interstitial sites between the C 60 molecules, while for a high pressure analogue Cs 3 C 60 the body centered cubic structure was found [65].…”

“…The highest transition temperature, T c = 40 K, was found under pressure for Cs 3 C 60 , which is not superconducting at ambient conditions [64,65]. Superconducting fullerides crystallize under normal pressure in a face centered regular structure with alkali metal ions residing in interstitial sites between the C 60 molecules, while for a high pressure analogue Cs 3 C 60 the body centered cubic structure was found [65]. Superconductivity in these materials is well described in terms of BCS-type s-wave approach, with large contribution of intramolecular fulleride phonons to the pairing mechanism [64].…”

Scanning probe measurements of CuI doped single-walled carbon nanotubes

“…5,6 Similar behavior was observed in fullerene C 60 compaunds where superconductivity was found in Rb or Cs doped samples. 7 Doping of carbon nanotubes alternates an electronic structure as a whole not only the value of the conductivity of carbon nanotubes 8 but the value of work function (Φ) 9 as well. Essential change of positions of conductance and valence band were also observed previously.…”