Comparative study of superconducting K 2CsC 60, Rb 3C 60 and Rb 2CsC 60

Abstract

High quality ternary and binary alkali metal doped C 60 compounds are investigated by using ac susceptibility techniques. The ac response χ = χ′ − iχ″ is studied as a function of temperature and applied ac magnetic field strength. The results are interpreted in terms of Bean's critical state model and clear experimental evidence for a linear temperature dependence of the intragrain critical current density j c(T) is given.