Preparation of cobalt ferrite nanoparticles via a novel solvothermal approach using divalent iron salt as precursors

Graphical abstract: CoFe2O4 nanoparticles are obtained via solvothermal approach using Fe2+ salt as iron resource. The magnetic properties can be modified by some additives. Display Omitted Highlights: ► CoFe2O4 nanoparticles are synthesized by a facile one-step novel solvothermal method. ► The system is firstly performed in water–glycol mixture solvent with an ordinary air surrounding. ► The ferrous ions are used as iron source without adding oxidant. ► It is firstly found the low-coercivity CoFe2O4 nanoparticles can be obtained with the help of some additives in the synthesis system. -- Abstract: Cobalt ferrite (CoFe2O4) nanoparticles are synthesized by a facile novel solvothermal method. The reactions are firstly performed in water–glycol system and Fe2+ salt is used as iron source without oxidant help. Some factors influenced the reactions, including temperature, reaction time, additives, are investigated. The samples are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM), respectively. The magnetic properties of some samples are detected by vibrating sample magnetometry techniques (VSM). It is firstly found that the magnetism of cobalt ferrites nanomaterials can be modified by some additives. The coercivity of CoFe2O4 nanoparticles evidently decreases from 600 to 50 Oe in the presence of PEG-4000 in the system.