NOVEL SUPERSTRUCTURES OF ALKALI-DOPED C₆₀ FILMS ON Cu(111) AND Ag(111) SURFACES

Abstract

We report a scanning tunneling microscopy (STM) study of potassium ( K )-doped C 60 ( K x C 60 ) on Cu (111) and Ag (111), with focus on the observation of novel K -induced superstructures. On Cu (111), K -intercalation leads to various superstructures, i.e., p(3 × 3), p(2 × 2), and a disordered "maze-like" structure. Concomitant removal of C 60 -induced substrate reconstruction was also observed. On Ag (111), K -doping induces C 60 reorientation and results in a p(2 × 2) superstructure. All observed superstructures suggest intrinsic inhomogeneity of K -doping in fullerene materials, which must be further understood.