Efficient route to large arrays of CNx nanofibers by pyrolysis of ferrocene/melamine mixtures

We report a high-yield route to two-dimensional arrays (< 400x400 mu m(2)) of aligned C49Nx (x less than or equal to 1) nanofibers (< 100 nm o.d.; < 60 mu m length), by pyrolyzing mixtures of ferrocene and melamine at 950-1050 degrees C under an Ar flow. The fibers exhibit unusual interlinked stacked-cone morphologies, ascribed to the presence of nitrogen. High-resolution electron energy-loss spectroscopy of the individual fibers reveals a 2% nitrogen content with ionization energies mainly at similar to 400.9 eV, corresponding to N bonded to three C atoms within a hexagonal framework. The nanofibers may be useful for the economic fabrication of field emission sources and robust composites. (C) 1999 American Institute of Physics. [S0003-6951(99)00351-4].