Synthesis and structure of alkaline earth and rare earth metal doped C70

We have investigated the structure sequence of alkaline earth (A=Ba, Sr) and rare earth metal (R=Eu) doped C70 binary system. X-ray diffraction measurements revealed that there exist at least four stable phases at x=3, 4, 6, and 9 in AxC70 and two stable phases at x=3, and 9 in RxC70. Among them, structural models are presented for Ba4C70, Sr3C70, and Eu3C70. Ba4C70 takes an analogous structure to orthorhombic Ba4C60. Sr3C70 and Eu3C70 have monoclinic cell and their diffraction patterns are quite similar to that of Sm3C70, which involves a unique C70-metal-C70 dimer structure. Preliminary results of Raman spectroscopy and magnetization measurement suggest the highly reduction state for A9C70 and ferromagnetic interaction for EuxC70