Effect of Na_2CO_3 on the microcrystalline structure of ultrafine Fe_2O_3 powders

Ultrafine γ Fe 2O 3 powders with high thermal stability were prepared via pyrolysis of the mixture of Fe(NO 3) 3·9H 2O, NaOH and stearic acid. The samples were characterized by IR,XRD and TEM. The experiment results showed that Na 2CO 3 formed during pyrolysis had an effect on stabilizing the crystalline structure and controlling the grain size. The mechanism has also been studied.