ICOSAHEDRAL BORON CARBIDE NANOCRYSTALS GROWN INSIDE DLC TEXTURE BY HFCVD

In this research, carbon nanostructures doped by boron atoms to synthesize Boron doped diamond like carbon (BDDLC), through DLC texture grown icosahedral boron carbide nanostructure to achievement used hot filament chemical vapor deposition (HFCVD) regime. Raman spectroscopy of BDDLC revealed two broad peaks centered on 1334 cm-1 and 1573 cm-1 , the origin of which is sp3 hybrid of disorder (D-band) and sp2 hybrid of graphite (G-band), respectively (Fig. 1). These peaks stem from aromatic compounds with sp2 hybrid, demonstrating a local collection of amorphous B4C on the substrate surface. Furthermore, D and G peaks are illustrative of more damage inside the structure. X-ray diffraction (XRD) characterization indicated significant peaks assigned to icosahedral (B13C2) structures in planes (012), (021), and (024). Particles size calculated by Debyescherrer formula is between 0.8-7 nm. Additionally, Tuinstra – Koenig formula at a 42-73 nm interval, evaluated the graphite grain size. The decrease observed in the intensity of G and D peaks may stem from disrupting the vibrational behavior of the film and diminution of polarizability in the molecules of the lattice. One of the factors inducing the decrease of polarizability may be the promotion of a great fraction of δ bonds between B-C atoms. Through cauliflowers morphology observed in field emission Scanning electron microscopy (FE-SEM) images (Fig. 2), it could be apparently seen that the increase of boron concentration leads to the augmentation of chain crack on the surface and raising the amount of doped boron gives rise to a smoother and more uniform surface. It was observed that the cracks on the surface increase by increasing boron doped in the grown film, as seen in Fig. 2 (a)-(d).