Results in Physics (Jan 2017)
The photoemission study of Sr-intercalated C60
Abstract
Motivated by the renaissance of fullerene superconductivity, research on fullerides has once more become a hot topic in physics and material science. Here, we investigate the electronic properties of the phases that are formed upon metal Sr intercalated C60 film in ultra-high vacuum by synchrotron-radiation photoemission spectroscopy. In order to obtain the phase pure sample, special attentions were taken to the annealing procedure during the sample preparation. We find that the sample changes from semiconductor (C60) to weak metallicity (Sr2C60) at low intercalation levels, and then to semiconductor (Sr3C60) at intermediate intercalation levels. At last, the sample turns out to be metallicity (Sr6C60) at high intercalation levels. These observations along with the previously electrical resistivity and magnetic susceptibility measurements shed light on the electronic structure of Sr fullerides. Keywords: Sr fullerides, Electronic structure, Photoemission spectroscopy