Phonon Dispersion Relation of Bulk Boron-Doped Graphitic Carbon

Bulk turbostratic graphitic carbon of varying levels of disorder and chemical compositions has been synthesized by a direct synthesis method in the temperature range of 750-1100 degrees C, with a focus on boron incorporation within the graphitic lattice. The atomistic and electronic/vibrational structures were characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy, Auger electron spectroscopy, X-ray absorption spectroscopy, and Raman spectroscopy. The phonon dispersion relation of graphitic carbon was found to be uniquely sensitive to substitutional boron doping, which perturbs the phonon structure while leaving the lattice structure unchanged. The dispersion relation of the D peak measured by Raman spectroscopy can be used to uniquely identify bulk graphitic materials containing a large content of ordered trigonal planar g-BC3 units, which are of high interest in applications ranging from hydrogen storage to lithium-ion batteries.