Met-Cars: mass deposition and preliminary structural study via TEM

Transition metal-carbon clusters, including metallocarbohedrenes (Met-Cars), are of great interest for their potential applications in nanodevices. Herein we provide evidence of cluster-assembled nanoscopic features formed by the mass-gated deposition of large metal-carbon clusters. Gas phase zirconium-carbon species, gated at the mass corresponding to the Met-Car composition (M8C12), were deposited onto carbon-covered grids under both hard- and soft-landing conditions. The resulting deposited materials were analyzed via high-resolution transmission electron microscopy (HRTEM). Hard-landing conditions were found to lead to the production of species having a structure corresponding to the well-known bulk metal carbide, while studies of soft-landed deposits of zirconium Met-Cars were found to form a FCC structure with lattice parameter similar to15 Angstrom, thus indicating cluster assembly. (C) 2003 Elsevier B.V. All rights reserved.