Microstructure and magnetic properties of nanocrystalline Co1−xZnxFe2O4 ferrites

• Published in: Materials research bulletin Vol. 47; no. 12; pp. 4174 - 4180
• Main Authors: Liu, Yin, Zhu, Xiao-guang, Zhang, Lei, Min, Fan-fei, Zhang, Ming-xu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2012
• Subjects: A. Magnetic materials; A. Nanostructures; B. Chemical synthesis; B. Magnetic properties; B. Chemical synthesis; A. Magnetic materials; B. Magnetic properties; A. Nanostructures
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2012.08.076

TEM of nanocrystalline Co0.5Zn0.5Fe2O4 ferrite calcined at 973K for 1.5h. [Display omitted] ► Nanocrystalline Co1−xZnxFe2O4 ferrites powder were prepared by the spraying-coprecipitation method. ► The enhancement of the magnetization for nanocrystalline Co0.7Zn0.3Fe2O4 ferrite is obtained. ► The mechanism of synthesis of the spraying-coprecipitation method was discussed. ► Magnetic behavior with a significantly enhanced coercivity value of about 7.6×103Am−1 in Co0.5Zn0.5Fe2O4 ferrite. Nanocrystalline Co1−xZnxFe2O4 ferrites with spinel phase were prepared by a spraying-coprecipitation method. Experimental results indicate that the average grain size of Co1−xZnxFe2O4 ferrites calcined at 973K for 1.5h is about 32nm and more uniform. The obtained smaller and more uniform particle size can be ascribed to the effect of entrainment and turbulence for jet in the spraying-coprecipitation approach. Magnetic property shows that the saturation magnetization of the nanocrystalline Co0.7Zn0.3Fe2O4 ferrite is enhanced to 83.4Am2kg−1. Moreover, the remanent magnetization and coercivity of nanocrystalline Co1−xZnxFe2O4 ferrites decrease with the increase of zinc concentration. The specific saturation magnetization and remanent magnetization of Co0.5Zn0.5Fe2O4 ferrite increases with the increasing grain size. The maximum coercivity of Co0.5Zn0.5Fe2O4 ferrite reaches up to 7.6×103Am−1, as the grain size is 32nm. The value of ferromagnetic exchange length in Co0.5Zn0.5Fe2O4 ferrite is about 42nm. The magnetic behavior of Co0.5Zn0.5Fe2O4 ferrites may be attributed to the effect of nanometer size of magnetic particles.