title: Low temperature synthesis of magnetite and maghemite nanoparticles.
abstract: We report on the synthesis of iron oxide nanoparticles below 100 degrees C by a simple chemical protocol. The uniqueness of the method lies in the use of Ferrous ammonium sulphate (in conjugation with FeCl3) which helps maintain the stability of Fe2+ state in the reaction sequence thereby controlling the phase formation. Hexamine was added as the stabilizer. The nanoparticles synthesized at three different temperatures viz, 5 degrees, 27 degrees, and 95 degrees C are characterized by several techniques. Generally, when a mixture of Fe3+ and Fe2+ is added to sodium hydroxide, alpha-Fe2O3 (the anti-ferromagnetic phase) is formed after the dehydration process of the hydroxide. In our case however, the phases formed at all the three temperatures were found to be ferro (ferri) magnetic, implying modification of the formation chemistry due to the specifics of our method. The nanoparticles synthesized at the lowest temperature exhibit magnetite phase, while increase in growth temperature to 95 degrees C leads to the maghemite phase.
authors.affiliation: Department of Chemistry, University of Pune, Pune 411007, India.
authors.forename: Shrikant
authors.initials: S
authors.lastname: Bhagwat
authors.forename: Hema
authors.initials: H
authors.lastname: Singh
authors.forename: Anjali
authors.initials: A
authors.lastname: Athawale
authors.forename: Beatrice
authors.initials: B
authors.lastname: Hannoyer
authors.forename: Samuel
authors.initials: S
authors.lastname: Jouen
authors.forename: Benoit
authors.initials: B
authors.lastname: Lefez
authors.forename: Darshan
authors.initials: D
authors.lastname: Kundaliya
authors.forename: Renu
authors.initials: R
authors.lastname: Pasricha
authors.forename: Shailaja
authors.initials: S
authors.lastname: Kulkarni
authors.forename: Satishchandra
authors.initials: S
authors.lastname: Ogale