中国物理B ›› 2013, Vol. 22 ›› Issue (10): 107101-107101.doi: 10.1088/1674-1056/22/10/107101

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Growth of monodisperse nanospheres of MnFe2O4 with enhanced magnetic and optical properties

M. Yasir Rafiquea b, 潘礼庆a, Qurat-ul-ain Javedb, M. Zubair Iqbalb, 邱红梅b, M. Hassan Farooqc, 郭振刚b, M. Tanveerd   

  1. a College of Science and Research Institute for New Energy, China Three Gorges University, Yichang 443002, China ;
    b Department of Physics, University of Science and Technology of Beijing, Beijing 100083, China;
    c School of Material Science and Engineering, University of Science and Technology of Beijing, Beijing 100083, China;
    d Research Center of Materials Science, Beijing Institute of Technology, Beijing 100081, China
  • 收稿日期:2013-02-06 修回日期:2013-04-03 出版日期:2013-08-30 发布日期:2013-08-30
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 50472092, 50672008, and 50971023), the Beijing Natural Science Foundation (Preparation and Magnetic Properties of Ferromagnetic Nanoring Lattice), and Research Foundation for Talented Scholars of China Three Gorges University. M. Y. Rafique was also supported by the Chancellor Scholarship of the University of Science and Technology of Beijing.

Growth of monodisperse nanospheres of MnFe2O4 with enhanced magnetic and optical properties

M. Yasir Rafiquea b, Pan Li-Qing (潘礼庆)a, Qurat-ul-ain Javedb, M. Zubair Iqbalb, Qiu Hong-Mei (邱红梅)b, M. Hassan Farooqc, Guo Zhen-Gang (郭振刚)b, M. Tanveerd   

  1. a College of Science and Research Institute for New Energy, China Three Gorges University, Yichang 443002, China ;
    b Department of Physics, University of Science and Technology of Beijing, Beijing 100083, China;
    c School of Material Science and Engineering, University of Science and Technology of Beijing, Beijing 100083, China;
    d Research Center of Materials Science, Beijing Institute of Technology, Beijing 100081, China
  • Received:2013-02-06 Revised:2013-04-03 Online:2013-08-30 Published:2013-08-30
  • Contact: Pan Li-Qing E-mail:lpan@ctgu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 50472092, 50672008, and 50971023), the Beijing Natural Science Foundation (Preparation and Magnetic Properties of Ferromagnetic Nanoring Lattice), and Research Foundation for Talented Scholars of China Three Gorges University. M. Y. Rafique was also supported by the Chancellor Scholarship of the University of Science and Technology of Beijing.

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摘要： Highly dispersive nanospheres of MnFe2O4 are prepared by template free hydrothermal method. The nanospheres have 47.3-nm average diameter, narrow size distribution, and good crystallinity with average crystallite size about 22 nm. The reaction temperature strongly affects the morphology, and high temperature is found to be responsible for growth of uniform nanospheres. Raman spectroscopy reveals high purity of prepared nanospheres. High saturation magnetization (78.3 emu/g), low coercivity (45 Oe, 1 Oe=79.5775 A·cm-1), low remanence (5.32 emu/g), and high anisotropy constant 2.84×104 J/m3 (10 times larger than bulk) are observed at room temperatures. The nearly superparamagnetic behavior is due to comparable size of nanospheres with superparamagnetic critical diameter Dcrspm. The high value of Keff may be due to coupling between the pinned moment in the amorphous shell and the magnetic moment in the core of the nanospheres. The nanospheres show prominent optical absorption in the visible region, and the indirect band gap is estimated to be 0.98 eV from the transmission spectrum. The prepared Mn ferrite has potential applications in biomedicine and photocatalysis.

关键词: Mn ferrite, magnetic materials, hydrothermal method, superparamagnetic, Raman spectroscopy

Abstract: Highly dispersive nanospheres of MnFe2O4 are prepared by template free hydrothermal method. The nanospheres have 47.3-nm average diameter, narrow size distribution, and good crystallinity with average crystallite size about 22 nm. The reaction temperature strongly affects the morphology, and high temperature is found to be responsible for growth of uniform nanospheres. Raman spectroscopy reveals high purity of prepared nanospheres. High saturation magnetization (78.3 emu/g), low coercivity (45 Oe, 1 Oe=79.5775 A·cm-1), low remanence (5.32 emu/g), and high anisotropy constant 2.84×104 J/m3 (10 times larger than bulk) are observed at room temperatures. The nearly superparamagnetic behavior is due to comparable size of nanospheres with superparamagnetic critical diameter Dcrspm. The high value of Keff may be due to coupling between the pinned moment in the amorphous shell and the magnetic moment in the core of the nanospheres. The nanospheres show prominent optical absorption in the visible region, and the indirect band gap is estimated to be 0.98 eV from the transmission spectrum. The prepared Mn ferrite has potential applications in biomedicine and photocatalysis.

Key words: Mn ferrite, magnetic materials, hydrothermal method, superparamagnetic, Raman spectroscopy

中图分类号:  (Fermi-liquid theory and other phenomenological models)

  • 71.10.Ay
75.50.-y (Studies of specific magnetic materials) 75.75.-c (Magnetic properties of nanostructures) 78.67.Bf (Nanocrystals, nanoparticles, and nanoclusters)