Temperature-controlled synthesis of novel boron nanofibers by laser ablation technique

The synthesis of boron nanofibers (BNFs) at different temperatures using the double-pulsed laser ablation (DPLA) technique were reported. Q-switched Nd: YAG laser with 532 and 1064 nm dual beam wavelengths of laser used to ablate a solid boron target. A vapor–solid process at a furnace temperature and pressure supported boron 'nanofibers' growth with the active metal catalysts of 1 % Ni and 1 % Co in a quartz tube furnace in flowing argon (Ar) gas. The crystalline phase purity of the synthesized BNFs at 950, 1050, and 1150 °C were determined by X-ray diffraction (XRD), and the results from XRD confirm that each BNF is preferentially grown in the c-axis (100) direction of alpha boron (α-B). Electron microscopy revealed that each BNF exhibit a length of 1–5 μm and a diameter width of 5–100 nm, while the elemental chemical compositional nature of the BNFs is identified from energy dispersive X–ray spectroscopy (EDX). Image analysis shows the average diameter of each BNF synthesized to be 23.10, 19.13, and 16.09 nm. The lattice distance of each BNF is found to be 0.40, 0.39, and 0.38 nm, respectively. Fingerprint Raman spectroscopy revealed the fundamental vibrational modes of BNFs at Eg and A1g. The Growth Mechanism of BNFs at 950°C, 1050°C and 1150°CAdebisi et al. report on the synthesis of boron nanofibers at different temperatures. The dual-pulsed lasers at 532 nm and 1064 nm ablate a boron target contained metal catalysts of nickel and cobalt in a furnace at temperatures of 950 °C, 1050 °C, and 1150 °C. The hot laser induced plasma, in the presence of bimetallic transitional catalysts, a flowing laminar argon gas creates conditions that are conducive to the nucleation of crystalline boron nanofibers. The as-prepared materials are characterized by optical and electron spectroscopies. A schematic diagram of the proposed LACVD crystal growth mechanism of boron nanofibers synthesized at 950 °C, 1050 °C and 1150 °C. [Display omitted] •Nucleation and growth are initiated at the centre of the furnace in the region of initial laser ablation.•The nucleation and growth of BNFs occurs along the c-axis direction of α-boron.•As the laser ablation plume condenses and cools, the nanofibers elongate along the (100) plane.•Thermodynamic conditions influence the nucleation and growth BNF.•Each BNF, is swept to the back of the quartz tube by the flowing argon gas.