Growth and FIB-SEM analyses of C60 microtubes vertically synthesized on porous alumina membranes

The vertical growth of C60 microtubes (C60MTs) on anodic aluminum oxide (AAO) membranes was investigated. The C60MT size dependence on isopropyl alcohol (IPA) injection rate, into C60-saturated toluene solutions through AAO membranes, was measured. A longitudinal section of the interface between a vertically grown C60MT (V-C60MT) and a membrane was prepared by focused ion beam processing, and observed with scanning electron microscopy. No cracking was observed along the interface, suggesting good bonding. V-C60MTs exhibited spiral growth. V-C60MT planar density, wall thickness and aspect ratio all decreased with increasing IPA injection rate. The relationships among length, inner and outer diameters of V-C60MTs were also investigated by varying IPA injection rate.