Studies on the magnetism of cobalt ferrite nanocrystals synthesized by hydrothermal method

Journal Article · Fri Feb 15 00:00:00 EST 2008 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2007.10.034· OSTI ID:21043884

Lijun, Zhao ^[1]; Yan, Xing; Shuyan, Song; Shiyong, Yu; Weidong, Shi; Xianmin, Guo; Jianhui, Yang; Yongqian, Lei; Feng, Cao ^[1]

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1. Key Laboratory of Rare Earth Chemistry and Physics, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

Fe-Co/CoFe{sub 2}O{sub 4} nanocomposite and CoFe{sub 2}O{sub 4} nanopowders were prepared by the hydrothermal method. The structure of magnetic powders were characterized by X-ray diffraction diffractometer (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), thermal gravity analysis (TGA) and differential thermal analysis (DTA) analysis, X-ray photoelectron spectrometry (XPS), and Fourier transform infrared spectra (FTIR) techniques, while magnetic properties were determined by using a vibrating sample magnetometer (VSM) at room temperature. The effects of hydrothermal reaction conditions on magnetic properties were also discussed in details. The values of saturation magnetization (M{sub s}) and coercive fore (H{sub c}) for Fe-Co/CoFe{sub 2}O{sub 4} nanocomposite are 113 emu/g and 1.4 kOe, respectively. Furthermore, CoFe{sub 2}O{sub 4} ferrite with a single-domain critical size of 70 nm was fabricated by controlling the hydrothermal reaction conditions carefully, which presents high coercive force (ca. 4.6 kOe) and high squareness ratio (ca. 0.65). One interesting thing is M{sub s} value of CoFe{sub 2}O{sub 4} ferrite with a diameter of 40 nm is 86 emu/g which is comparable to that of the bulk counterpart. - Graphical abstract: CoFe{sub 2}O{sub 4} ferrite with a single-domain critical size of 70 nm was fabricated by controlling the hydrothermal reaction conditions carefully, which presents high coercive force (ca. 4.6 kOe) and high squareness ratio (ca. 0.65)

• OSTI ID: 21043884
• Journal Information: Journal of Solid State Chemistry, Vol. 181, Issue 2; Other Information: DOI: 10.1016/j.jssc.2007.10.034; PII: S0022-4596(07)00449-5; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
COBALT OXIDES
COERCIVE FORCE
CRITICAL SIZE
DIFFERENTIAL THERMAL ANALYSIS
FERRITES
FOURIER TRANSFORMATION
HYDROTHERMAL SYNTHESIS
INFRARED SPECTRA
MAGNETIC PROPERTIES
MAGNETISM
MAGNETIZATION
NANOSTRUCTURES
SCANNING ELECTRON MICROSCOPY
TEMPERATURE RANGE 0273-0400 K
THERMAL GRAVIMETRIC ANALYSIS
TRANSMISSION ELECTRON MICROSCOPY
VIBRATING SAMPLE MAGNETOMETERS
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY