Synthesis and x-ray diffraction of intercalation compounds of C-70

A synthesis of several donor-type and acceptor-type C-70 intercalation compounds was studied using x-ray diffraction measurements. A structure sequence of doped fcc(x=1), bct(x=4), bcc(x=6) and M-saturated fcc(x=9) phases was observed in MxC70(M=K,Rb,Cs) with increasing M concentration. A doped fcc phase(x=3) was observed in KxC70, C70Ix had two bct phases(x=2,4). C(70)A(x)(A=ICI, ICI3, IBr) had also successfully synthesized. Superconductivity in each phase was checked using ac magnetic-susceptibility measurements. All these phases were nonsuperconducting down to 1.3 K. Electrical-conductivity measurements on K doped thin film of C-70 and magnetic-susceptibility measurements on RbxC70 are reported.