Characteristic of interface effect in Cu-C-60 granular films

In this letter, Cu-C-60 granular film is prepared with coevaporation method at room temperature. The conductance of the film is measured by in situ me thod, and its microstructure is characterized by transmission electron micr oscopy. The charge transfer from Cu to C-60 is investigated with Raman spec troscopy. The results indicate that the sample has the uniformly granular m icrostructure. The interaction between C-60 and Cu at the Cu-C-60 interface s, which significantly affects the orientational order-disorder phase trans ition of C-60 and induces the phase transition of C-60 in the temperature r ange from 219 to 248 K. The mechanism of the characteristic of such phase t ransition is discussed. (C) 2000 American Institute of Physics. [S0003-6951 (00)04731-8].