Synthesis and processing of magnetic nanoparticles

•Coprecipitation and thermal decomposition are the most useful processes.•Coprecipitation gives directly water dispersible NPs.•Thermal decomposition allows a good control of the size and shape.•Thermal decomposition leads to NPs with a high crystallization.

Inorganic nanomaterials and their unique physical properties are the center of modern material science due to their potential technological importance. Among the existing structures, magnetic iron oxide nanoparticles (MNPs), including magnetite (Fe3O4) and maghemite (γ-Fe2O3), exhibit remarkable magnetic properties, called ‘superparamagnetism’, making these nanostructures suitable for a wide range of applications. Because their physico-chemical properties play an important role in major applications, our review focuses on the synthesis approaches giving rise to the best control of size and shape.