Formation of One-Dimensional C60 Rows on TiO2(110)-1×2 and Structural Change of C60 Adlayers Induced by Electron Irradiation

Abstract

Adsorption and growth of C60 adlayers on a TiO2(110)-1×2-cross-link structure were investigated by scanning tunneling microscopy (STM). A single C60 molecule was preferentially anchored at the cross-link site due to interaction with undercoordinated Ti cations. A C60 adlayer grew as domains brought about by intermolecular van der Waals force and a monolayer covered the whole surface. The monolayer structure is characterized by paired C60 rows running along the added rows of the substrate. C60 molecules are closely packed along the rows as in the case of the C60 crystal (1.0 nm separation), whereas the separation between the paired rows is larger (1.1 nm). Thus, a one-dimensional nature can be expected for a subsequent process. Polymerization of C60 molecules for the C60 adlayers by electron beam irradiation was examined as a nanofabrication process. However, inhomogeneous polymerization occurred particularly for the first C60 adlayer.