Synthesis, Structure, and Transport Properties of Novel Fullerides A₃C₇₀ (A = Ba and Sm)

Abstract

A series of new stable fullerides A3C70 (A = Sm, Ba) has been synthesized using solid-state reactions. The structure of Sm3C70 has been identified to be monoclinic by simulation of synchrotron powder diffraction data. The structure of Ba3C70 is derived from the A15 structure adopted by Ba3C60. The low symmetry relative to C60 fullerides could be an important factor in the absence of superconductivity in C70 fullerides. The electronic transport can be explained by a variable-range hopping mechanism for A3C70 (A = Ba, Sm) samples, while the transport for SmxC70 (x > 3) samples appears to be dominated by weak localization (WL) theory.