Synthesis of NiFe2O4 nanoparticles by a low temperature microwave-assisted ball milling technique

Nanocrystalline NiFe2O4 particles with mean size of about 20 nm were directly synthesized by a novel microwave-assisted ball-milling approach, using basic nickel carbonate and iron powders as the raw materials. The results showed that an intermediate product Fe2Ni2(OH)(8)CO3 center dot 2H(2)O was formed by milling NiCO3 center dot 2Ni(OH)(2)center dot 4H(2)O and Fe powders with microwave assistance, then this intermediate product further reacted to form NiFe2O4 nanocrystals. On the other hand, by using NiO and Fe2O3 as the raw materials, NiFe2O4 could not be able to form. NiFe2O4 nanocrystals could be directly synthesized without post-sintering by this process. This makes it a new promising approach for ferrite nanoparticle, which is simple and environmentally friendly.