Carbon nanostructure on a tungsten needle tip formed by electron beam induced deposition and its graphitization through resistive heating

Using ferrocene as a precursor, an amorphous carbon nanorod was fabricated on a tungsten needle tip by electron beam induced deposition inside an ultrahigh-vacuum scanning electron microscope at room temperature. This needle tip was driven by a stepping motor and pizeo-driving device to make contact with a molybdenum substrate inside a specially designed transmission electron microscope (TEM) specimen holder. A 100 μA current flowed through this nanorod and resistance heating was induced. Within 120s, the original amorphous carbon nanorod was transformed into graphite nanostructures by this thermal energy. This phase transformation process was confirmed by high-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS). After applying a current of 120s, graphite sheets with 0.34 nm lattice spacing in HRTEM image and π bonding peak in EELS spectra were detected from the nanorod, which were not detected before that treatment.