Dear All: I interested to know about the production/synthesis of iron oxide nanoparticles. At present, which method/process is adopted in chemical companies for the production of magnetite (Fe3O4)? May be for production of 1 kg per day? The size may be around 50 nm. I also wanted to know: In laboratory one can prepare even 5 nm sized Fe3O4 nanoparticles. Can some one tell me about the cheapest and easiest method of preparing Fe3O4 nanoparticles (may be less than 10 nm size) in lab scale? Thank you for your help. Regards, Rajini.