In situ conductivity study of the phase transition in Sb-doped C60

Abstract

C 60 /Sb bilayers were prepared on the substrate of mica, and their electrical properties were investigated by in situ dc conductivity measurements. The results indicate that the Sb doping in C60 significantly affects the critical temperature (Tc) for the orientational order–disorder transition of C60. The Tc of Sb-doped C60 increases to about 278 K, ∼18 K higher than that of the pristine C60. This transition is sensitive to Sb content and disappears upon annealing. A possible mechanism of such a phase transition is discussed.