PROCESS FOR PRODUCING MAGNETIC NANOCOMPOSITES BASED ON IRON OXIDE

There are a multitude of methods for producing magnetic nanoparticles with a given magnetic behavior (paramagnetic, ferromagnetic, etc.) and a given magnetic category (soft, semi-hard, hard). But for the same composition of precursors and a given process, there is still no simple and effective way to modulate the magnetic category. Based on coprecipitation of precursors and a hydrothermal and/or solvothermal synthesis, this innovative production process allows to easily choose the magnetic category (soft, semi-hard, hard) of the nanocomposites while using the same composition of precursors.

Applications: 

• Ferrofluids, magneto-rhéological fluids
• Electromagnetic shielding
• Water/soil traitement
• Catalysis
• Energy storage
• Therapeutics and diagnosis
• Antibacterial activity

Competitive advantages:

• Possible to obtain different magnetic materials (soft, semi-hard, and hard) while using the same composition
• The coercive field is adjustable according to the synthesis conditions.
• High purity (only presence of Co, Fe, Pr, and O based on an EDX analysis by MET)
• Large range of particle size possible : from 1nm to 500nm or more
• High Specific Surface Area (250-750 m²/g with 5nm nanospheres, depending on the particles shape)
• Low bulk density (< 5 g/cm3)
• No theoretical limit for the injection of these NPs into another material (just below a certain temperature to avoid loss of the secondary phases)

Keywords: Nanoparticles, Ferrites, Solvothermal, Hydrothermal, Magnetic