We report a new type of organometallic system, Ag-toluylene 2,4-dicarbamidonitrite (TDCN) composite thin film, for
ultrahigh density data storage devices by scanning tunneling microscopy (STM). The Ag-TDCN thin film was prepared on a
highly oriented pyrolytic graphite (HOPG) substrate using an ionized-cluster-beam (ICB) deposition method. Marks can be
created on the thin film by employing a voltage pulse between the STM tip and the surface of the HOPG substrate. The size
of the created marks is about 50 nm and the corresponding data storage density is about 10 l] bits/cm 2. The mechanism for
the data storage can be attributed to the conductance transition in the complex system. This result shows a great potential for
this new kind of organometallic composite system to find application in ultrahigh density data storage. © 1997 Published by
Elsevier Science B.V.