title: Alignment of Amorphous Iron Oxide Clusters: A Non-Classical Mechanism for Magnetite Formation.
abstract: Despite numerous studies on the nucleation and crystallization of iron (oxyhydr)oxides, the roles of species developing during the early stages, especially primary clusters and intermediate amorphous particles, are still poorly understood. Herein, both ligand-free and ligand-protected amorphous iron oxide (AIO) clusters (<2 nm) were synthesized as precursors for magnetite formation. Thermal annealing can crystallize the clusters into magnetite particles, and AIO bulk phases with domains of pre-aligned clusters are found to be direct precursors to crystals, suggesting a non-classical aggregation-based pathway that differs from the reported oriented attachment or particle accretion mechanisms.
authors.affiliation: State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Chemistry, Chemical Engineering and Biotechnology, Center for Advanced Low-Dimension Materials, Donghua University, Shanghai, 201620, China.
authors.forename: Shengtong
authors.initials: S
authors.lastname: Sun
authors.affiliation: Physical Chemistry, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany.
authors.forename: Denis
authors.initials: D
authors.lastname: Gebauer
authors.affiliation: Physical Chemistry, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Cölfen
keywords: aggregation; amorphous iron oxide; clusters; crystal growth; self-assembly