Enhanced Coercivity in Co-Rich Near-Stoichiometric CoxFe3-xO4+ Nanoparticles Prepared in Large Bat
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- 作者：German Salazar-Alvarez ; Richard T. Olsson ; Jordi Sort ; Waldemar A. A. Macedo ; José ; D. Ardisson ; Maria Dolors Baró ; Ulf W. Gedde ; Josep Nogué ; s
- 刊名：Chemistry of Materials
- 出版年：2007
- 出版时间：October 2, 2007
- 年：2007
- 卷：19
- 期：20
- 页码：4957 - 4963
- 全文大小：363K
- 年卷期：v.19,no.20(October 2, 2007)
- ISSN：1520-5002
文摘
The relationship between the structure and composition with the magnetic properties of nearstoichiometric cobalt ferrite nanoparticles CoxFe3-xO4+ (0.85 < x < 1.1) prepared in large batches withaverage sizes in the range 60-210 nm has been investigated. Chemical analysis and Rietveld refinementof the X-ray diffraction data in conjunction with Mössbauer spectroscopy allowed us to identify an interplaybetween particle size, microstructure (concentration of interstitial ions, microstrain, cation arrangementin octahedral and tetrahedral sites), and composition, which sensitively controls the magnetic propertiessuch as coercivity and saturation magnetization. In all cases, cobalt-rich compositions resulted in a highercoercivity, whereas lower degrees of inversion and higher iron contents led to slightly higher saturationmagnetization values.