title: Ultraporous single phase iron oxide-silica nanostructured aerogels from ferrous precursors.
abstract: Monoliths of iron oxide-silica aerogel nanocomposites have been synthesized using a novel synthesis route which consists of impregnating silica wet gels with anhydrous iron(II) precursors followed by ethanol supercritical drying of the gels. The process yields aerogels exhibiting high porosity, large surface areas (approximately 900 m2/g), rather low densities (approximately 0.6 g/cm3), and a homogeneous distribution of single-phase maghemite, gamma-Fe2O3, nanoparticles with average sizes in the 7-8 nm range. Remarkably, the gamma-Fe2O3 nanoparticles are obtained in the as-dried state without the need of postannealing. The nanoparticles are mostly superparamagnetic at room temperature but become blocked in a ferrimagnetic state at lower temperatures.
authors.affiliation: Institut de Ciència de Materials de Barcelona, Campus Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalunya, Spain.
authors.forename: Mihaela
authors.initials: M
authors.lastname: Popovici
authors.forename: Martí
authors.initials: M
authors.lastname: Gich
authors.forename: Anna
authors.initials: A
authors.lastname: Roig
authors.forename: Lluís
authors.initials: L
authors.lastname: Casas
authors.forename: Elies
authors.initials: E
authors.lastname: Molins
authors.forename: Cecilia
authors.initials: C
authors.lastname: Savii
authors.forename: Dumitru
authors.initials: D
authors.lastname: Becherescu
authors.forename: Jordi
authors.initials: J
authors.lastname: Sort
authors.forename: Santi
authors.initials: S
authors.lastname: Suriñach
authors.forename: Juan S
authors.initials: JS
authors.lastname: Muñoz
authors.forename: M Dolors
authors.initials: MD
authors.lastname: Baró
authors.forename: Josep
authors.initials: J
authors.lastname: Nogués