LOCAL TRANSFORMATION OF C(60) FULLERITE INTO A NEW AMORPHOUS PHASE OFCARBON USING A SCANNING TUNNELING MICROSCOPE

A scanning tunneling microscope (STM) has been used to locally transfo rm C60 molecules of a C60 fullerite thin film on Au(111) into a new am orphous form of carbon by application of a pressure in the GPa range. From the vertical tip movement during the transformation process, the local collapse of two monolayers of C60 is inferred. Based on atomical ly resolved STM images of this ''collapsed fullerite'' (CF) structure, a pair correlation function characteristic of an amorphous structure with a nearest-neighbor peak at 2.7 angstrom is presented here. The tw o-dimensional power spectrum of the real-space data exhibits no spots but rings, which are attributed to first and second nearest-neighbor d istances of the CF structure. An analysis of the number of nearest-nei ghbors of each atomic feature shows that about 50% of the atoms have i n-plane bonds to one other atom, and 40% have bonds to two other atoms .