High saturation magnetization Fe3O4 nanoparticles prepared by one-step reduction method in autoclave

Conformal magnetite nanoparticles are successfully prepared by one-step reduction method in the autoclave with controlled reduction conditions. The x-ray diffraction pattern indicates pure phase of Fe3O4 nanoparticles with high crystallinity were obtained. TEM analysis shows the presence of spherical nanoparticles with homogeneous size distribution of ∼20 nm. The obtained Fe3O4 nanoparticles have high saturation magnetization Ms of 75.3 emu·g−1. The inverse spinel Fe3O4 phase displays a distinct ferrimagnetic anisotropy. The Verwey metal-insulator transition of magnetite nanoparticles usually takes place at the blocking temperature of 120 K. The one-step reduction method in the autoclave of magnetite with well-controlled phase and high saturation magnetization in this work provides a promising opportunity for the synthesis of magnetic nano-materials to be used in wastewater treatment, catalyst, lithium-ion battery, contrast imaging, and especially in bio-applications.