Observation of self-assembled Mn$_{12}$-ac Molecules on Highly Ordered Pyrolytic Graphite

Thin films of the single molecule magnet Mn$_{12}$-ac have been deposited on Highly Ordered Pyrolytic Graphite (HOPG) by a solution evaporation method [1-3]. Mn$_{12}$-ac molecules in a well-ordered self-assembled triangular lattice were subsequently observed in these films by Scanning Tunneling Microscopy (STM) at room temperature under ambient conditions. STM images show typical center to center intermolecular separations of $\sim $ 5 nm. X-ray photoelectron spectroscopy shows that the self-assembled compound on the HOPG surface is consistent with Mn$_{12}$-ac and a control experiment demonstrated that it cannot be another species that may be present in the solvent. \newline [1] K. Kim et al., Appl. Phys. Lett. 85, 3872 (2004). \newline [2] D. M. Seo et al., J. Mag. Magn. Mater. 301, 31 (2006). \newline [3] D. Seo et al., J. Mag. Magn. Mater. in press (doi:10.1016/j.jmmm.2006.09.034).