Hydrothermal synthesis of magnetite crystals: From sheet to pseudo-octahedron

Journal Article · Wed Dec 15 00:00:00 EST 2010 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2010.09.023· OSTI ID:22209945

Hu, Ming; Ji, Rui-Ping ^[1]; Jiang, Ji-Sen ^[1]

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1. Department of Physics, Center of Functional Nanomaterials and Devices, East China Normal University, Shanghai 200241 (China)

In this paper, we developed a hydrothermal method to fabricate sheet-like and pseudo-octahedral magnetite crystals. X-ray diffraction (XRD) confirmed the products were pure spinel-structured magnetite. Scanning electron microscopy (SEM) was used to investigate the morphology of the obtained crystals. By carefully regulating the initial NaOH concentrations, the morphology of the products could be changed from sheet-like crystals to pseudo-octahedral crystals. Transmission electron microscopy (TEM) analysis indicated the sheet-like crystals were the oriented aggregation of nanoparticles. Pseudo-octahedral magnetite crystals were single crystalline, and were obtained by dissolution-recrystallization of the sheet-like crystals. Vibrating sample magnetometer (VSM)) suggested the magnetic properties of the products were strongly related to the morphology. The coercivity of the sheet-like magnetite crystals was 100 Oe, larger than 30 Oe of the pseudo-octahedral crystals, but the saturation magnetization of the sheet-like magnetite crystals was 40 emu/g, smaller than 85 emu/g of the pseudo-octahedral crystals.

• OSTI ID: 22209945
• Journal Information: Materials Research Bulletin, Vol. 45, Issue 12; Other Information: Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
COERCIVE FORCE
CRYSTAL GROWTH
HYDROTHERMAL SYNTHESIS
MAGNETIC MATERIALS
MAGNETIC PROPERTIES
MAGNETITE
MICROSTRUCTURE
MONOCRYSTALS
NANOSTRUCTURES
RECRYSTALLIZATION
SCANNING ELECTRON MICROSCOPY
TRANSMISSION ELECTRON MICROSCOPY
VIBRATING SAMPLE MAGNETOMETERS
X-RAY DIFFRACTION