| Boric acid (H3BO3) nanotubes, nanotips, nanorods, microtubes, and microtips were synthesized by exposing a thin film containing boron, carbon, and oxygen to a controllable humid atmosphere. X-ray photoelectron spectroscopy (XPS) and Secondary ion mass spectrometry (SIMS) were used to characterize the thin films. The boric acid structures were studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAD), and electron energy-loss spectrometry (EELS). The growth process of the boric acid structures was investigated. The dehydration kinetics of boric acid nanostructures in a vacuum was explored.; Single crystal magnesium borate (Mg2B2O5) nanowires with uniform diameter distribution were synthesized on MgO substrates by a chemical vapor deposition (CVD) method using boron triiodide and boric acid vapor (BI3/H3BO3) as a precursor and Platinum/Palladium (Pt/Pd) as catalysts. It is proposed that the growth mechanism of Mg2B2O5 nanowires is the Vapor-Liquid-Solid growth process. The conductivity of a single nanowire was measured to be about 10-4 O-1m-1. The CVD method was further developed to grow single crystal aluminum borate, including Al 18B4O33 and Al4B2O 9, nanowires and nanotubes using sapphire slides as substrates, NiB powder, Pt powder or Al films as catalysts. The growth process of the aluminum borate nanowires and nanotubes was studied. All the metal borate nanostructures were characterized by SEM, TEM, XRD, SAD, EELS and X-ray energy-dispersive spectrometry (XEDS).; Single crystal iron boride (Fe3B) and boron iron silicon (Fe 5Si2B) nanowires were synthesized by a CVD method using boron triiodide (BI3) and iron iodide (FeI2) as precursors. The Fe3B nanowires can either grow on Pt and Pd (Pt/Pd) coated sapphire, Pt/Pd coated fused silica, bare silicon (Si) or bare silicon oxide (SiO2) on Si substrates. The Fe5Si2B nanowires can form on bare Si or bare SiO2 on Si substrates. SEM, TEM, SAD, EELS and XEDS were employed to study these novel materials. Room temperature magnetic force microscopy (MFM) investigations on the Fe3B nanowires suggest that they are ferromagnetic nanowires with a single domain configuration. The growth processes of Fe3B and Fe5Si2B nanowires were investigated. |
