Fe 3 O 4 nanoparticles synthesized by one-step reduction with nanoscale size-dependent magnetic properties

Magnetic Fe 3 O 4 nanoparticles (NPs) were successfully synthesized by the one-step reduction method. The microstructure, morphology, and magnetic properties were characterized by XRD, SEM, TEM, and vibrating sample magnetometer. Characterization results confirmed that the as-synthesized Fe 3 O 4 NPs had high purity and nearly spherical shape with an average crystallite size varied from 44 nm to 65 nm. The synthesized Fe 3 O 4 NPs exhibited excellent magnetic properties, including high saturation magnetization ( M s = 93 emu/g), low coercivity ( H c = 110 Oe) and remanence ( M r = 18.6 emu/g), and high magnetic response (5 s). Among that, the M s 93 emu/g value of the synthesized Fe 3 O 4 NPs is higher than other methods. The size how to effects on nanoparticles’ magnetic performance were discussed in detail. Including the reason that H c and M r of the NPs fell off with increasing average grain size. These results provided a new platform for further study of highly magnetic Fe 3 O 4 NPs. Graphical abstract