Abstract
The magnetite nanoparticles were synthesized through a process including dissolution of Fe(OH)2 and precipitation of an oxidized phase under ultrasonic irradiation in an aqueous solution. It was found that the ultrasonic irradiation accelerated the formation of magnetite. The crystallinity and magnetic properties of the magnetite particles synthesized under ultrasonic irradiation were better than those synthesized under mechanical stirring. The effects of dissolved gas and pH value were also studied. The dissolved gas was important to the effect of ultrasound on the formation of magnetite and the properties of particles were different when different gases were used as dissolved gas in the sonochemical synthesis of magnetite. The magnetite particles were successfully synthesized even at a neutral solution under ultrasonic irradiation. The low pH value delayed the formation of magnetite and affected the morphology of magnetite particles.
