Nucleation and submonolayer growth of C60 on KBr -: art. no. 096102

Noncontact atomic force microscopy has been applied to the prototypical molecule-insulator system C-60 on KBr to study nucleation and submonolayer growth. Overview images reveal an island growth mode with unusual branching structures. Simultaneous molecular and atomic resolution on the C-60 and KBr surfaces, respectively, was obtained revealing a coincident 8x3 superstructure. Also, a 21 +/- 3 pm apparent height difference was observed in atomic force microscopy topographies between some first layer molecules. One of the initial nucleation sites of the C-60 islands was determined by observation of loosely bound molecules at kink sites in monatomic KBr steps, in conjunction with the observation that islands form preferentially at step edges.