1. Magnetite nanoparticles prepared by the glass crystallization method and their physical properties
- Author
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P. Görnert, Christian Rüssel, R. Hiergeist, and S. Woltz
- Subjects
Materials science ,Annealing (metallurgy) ,Analytical chemistry ,Condensed Matter Physics ,Magnetic hysteresis ,Nanocrystalline material ,Electronic, Optical and Magnetic Materials ,law.invention ,Magnetization ,chemistry.chemical_compound ,Nuclear magnetic resonance ,Ferromagnetism ,chemistry ,law ,Curie temperature ,Crystallization ,Magnetite - Abstract
Glass melts in the system Fe 2 O 3 /FeO/CaO/Na 2 O/B 2 O 3 were prepared from the raw materials, by firstly reducing them by flushing with nitrogen and subsequently roller quenching. The flakes obtained had a thickness of around 150 μm and were thermally treated at temperatures in the range from 550 to 620 °C. X-ray diffraction gave evidence of the occurrence of nanocrystalline magnetite. Magnetization measurements at room temperature show ferromagnetic behaviour and no hysteresis. Temperature-dependent measurements showed a monotonic decrease of the saturation magnetization with temperature, and a Curie temperature of 553 °C. The primary mean particle core diameter is around 10 nm after annealing at 570 °C.
- Published
- 2006
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