Hydrothermal synthesis and characterization of single-crystalline Fe3O4 nanowires with high aspect ratio and uniformity

Uniform, ultra-thin, single-crystalline Fe3O4 nanowires with narrow diameter distribution centered at 15 nm and length up to several microns, were synthesized by a simple hydrothermal route with the assistance of polyethylene glycol (PEG) 400. The morphologies and structure of the obtained nanowires were examined by means of X-ray diffraction (XRD), Mössbauer spectrum, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The effect of PEG content and molecular weight on the yield and morphology of Fe3O4 nanowires was investigated. Saturation magnetization of Fe3O4 nanowires was determined to be 23.0 emu/g, which is distinctly lower than that of Fe3O4 nanoparticles.