Raman Characterization of the Phase Transition of Ion Implanted Hexagonal Boron Nitride to cubic Boron Nitride Nanoparticles

We investigated the phase transition of hexagonal boron nitride (h-BN) to the c-BN form by the ion implantation process. Raman Spectroscopy was the major technique used in the characterization of the possible h-BN - c-BN phase transformation. The hexagonal BN samples were implanted with various ions
including helium, lithium and boron, at different ion fluences ranging from 1×1016 ions/cm2 to 1×1016 ions/cm2. The effect of varying the ion implantation energies ranging from 40 keV to 160keV were also investigated on samples implanted by helium ions. Finally lithium implanted samples was studied using the 488 nm and 514 nm Raman laser lines. Micro Raman spectroscopy (µ-RS) measurements indicated that indeed ion implantation induced a phase change to the h-BN, evident from the longitudinal optical (LO) peaks at wavenumbers 1298 cm−1 and 1304 cm−1 appearing in the spectra after implantation. The nature and extent of these new peaks, and their dependence on the different implantation parameters is discussed.