Superconductivity of Fullerides with Composition AGa$_{x}$C$_{60}$ and AGa$_{x}$M$_{y}$C$_{60}$ (A = K, Rb; M = In, Sn, Bi)

Abstract

The new heterofullerides with the composition AGa$_{x}$C$_{60}$ and AGa$_{x}$M$_{y}$C$_{60}$ (A = K, Rb; M = In, Sn, Bi; $x,y<1$) have been synthesized by a new method using liquid alloys of alkali metal with gallium or gallams. The temperature dependence of the magnetic susceptibility was measured in the temperature range from 4.2 to 100 K, and transitions to a superconducting state were observed at temperatures $T_\mathrm{{c}}$ ranging from 7 to 17.5 K. The superconductivity was found for fullerides RbGa$_{x}$C$_{60}$ and RbGa$_{x}$In$_{y}$C$_{60}$ with orthorhombic lattice.