Nickel nanoparticles in carbon structures prepared by solid-phase pyrolysis of nickel-phthalocyanine

By using a modified method of solid-phase pyrolysis of metal-phthalocyanines, we have synthesized ferromagnetic Ni nanoparticles in different carbon structures: amorphous carbon plates, multiwall carbon nanotubes, carbon fibers, and graphitized capsules. The composition, structure and morphology of prepared composite materials have been studied by energy dispersive X-ray microanalysis, scanning and transmission electron microscopy, and X-ray diffraction technique. It has been found that the sizes of nickel nanoparticles (10-500 nm) and the type of carbon structures strongly depend on the pyrolysis conditions. By using the X-band ferromagnetic resonance measurements, we have revealed features of the temperature dependence of resonance spectra of single-domain and multi-domain Ni nanoparticles in Ni/C composites.