Disappearing of the Verwey Transition in Magnetite Nanoparticles Synthesized under a Magnetic Feld: Implications for the Origin of Charge Ordering
It is observed that Fe3O4 nanoparticles exhibit a Verwey transition at approximately 120 K, in agreement with that observed in the corresponding bulk sample. While, the transition vanishes in the Fe3O4nanoparticles formed under a 0.25 T magnetic field. It is found that the magnetic field induced oxidation of part of the Fe2+ ions on octahedral sites from lower spin states to higher spin states (Fe3+) during the formation of the nanoparticles, and then resulted in the vanishing of charge ordering between Fe2+ and Fe3+on the octahedral sites below Verwey transition temperature (TV) due to lacking of Fe2+ in some layers.
Peng, Zhenmeng, "Disappearing of the Verwey Transition in Magnetite Nanoparticles Synthesized under a Magnetic Feld: Implications for the Origin of Charge Ordering" (2004). Chemical and Biomolecular Engineering Faculty Research. 294.