PHYSICAL PROPERTIES OF METALLOFULLERENES IN SOLID, THIN FILM AND NANOMETER SCALE

摘要

Structures and physical properties of metallofullerenes are studied by X-ray diffraction, XANES, Raman, electric transport and scanning tunneling microscope (STM) measurements. Furthermore, the field effect transistors (FET's) are fabricated with thin films of fullerenes, and their characteristics are studied. The molecular orientation of metallofullerene in the crystals has been found to be closely associated with the structural phase transition from the X-ray diffraction study of Ce endohedral C_(82) (Ce@C_(82)). The C_(60) FET shows an n-channel enhancement-type property, while the Dy@C_(82) FET shows an n-channel depletion-type property. The STM image of Dy@C_(82) molecules on a well-defined Si(111) - (7 x 7) surface is observed at 300 K, showing a random adsorption of molecules even after annealing at 200℃.