Spectroscopic characterization of Ag catalyzed silicon carbide nanowires deposited via CVD reactor (original) (raw)

The Ag-catalyzed silicon carbide nanowires (SiC-NWs) were synthesized by chemical vapour deposition reactor using Silicon powder, C 2 H 2 , H 2 as reactant and precursor gases. The as-synthesized thin films were characterized by atomic force microscopy, X-ray diffraction (XRD), Raman and Fourier Transform Infrared Spectroscopy (FTIR) techniques to evaluate its microstructural, structural and vibrational properties. The evolution of physic-chemical properties like network bonding, disorder distribution, and phonon characteristics are studied under the variation of H 2 flow rates. AFM topography reveals elongated, vertical nanowires of diameter 10-100 nm and length extended up to few mm long with increasing H 2 flow rate from 15 to 45 sccm maintaining a constant flow of C 2 H 2 at 5 sccm. XRD result confirmed that the crystallite size of SiC-NWs films increased with an H 2 flow rate from 15 to 45 sccm. The lattice strain of SiC-NWs film increases from 0.022 to 0.092 with increasing H 2 flowrate. FTIR spectra revealed the blue shift of SiC-LO peak confirmed strain in the chemical bonds. The phonon lifetime of Si-TO and SiC-TO decreases whereas it increases in the case of SiC-LO phonon with a higher H 2 flow rate.