Microfluidic synthesis of Fe nanoparticles

A microfluidic reactor process is demonstrated for the synthesis of worm-like Fe nanoparticles (NPs) at room temperature. These high aspect ratio shaped Fe NPs can be further transformed into large ellipsoid species with refined crystal structures and increased aggregation by way of a sonication process, evidenced by their transmission electron microscope (TEM) images, selected area electron diffraction (SAED), X-ray Diffraction (XRD), X-ray absorption near K-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS). Due to the compensation effects on the magnetic properties of NPs from their increased size, enhanced magnetic coupling, refined crystal structure and the reduced aspect ratio, the sonication-treated Fe NPs show a slightly enlarged coercivity (Hc), an enhanced saturation magnetization (Ms) and a slight suppress in the increased blocking temperature (Tb).