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ABSTRACT: This work presents a systematic investigation on the structural and magnetic properties of Co1−xZnxFe2O4 (0.5<x<0.75) nanoparticles synthesized by the chemical co-precipitation method. The X-ray diffraction analysis, the Fourier Transform Infrared (FTIR) and the Vibrating Sample Magnetometer were carried out at room temperature to study the micro-structural and magnetic properties. The X-ray measurements revealed the production of a broad single cubic phase with the crystallite size within the range of 6–10 nm. The FTIR measurements between 400 and 4000 cm−1 confirmed the intrinsic cation vibrations of the spinel structure. The magnetic measurements show that the saturation magnetization and coercivity decrease by increasing the zinc content. Furthermore, the results reveal that the sample with a chemical composition of Co0.3Zn0.7Fe2O4 exhibits the super-paramagnetic behavior and the Curie point of 97 °C.
Journal of Magnetism and Magnetic Materials 03/2012; 324(15):2397-2403. · 1.78 Impact Factor
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ABSTRACT: Cobalt ferrite nanoparticles were synthesized by the chemical co-precipitation, normal micelles and reverse micelles methods of iron and cobalt chlorides. X-ray diffraction analysis, Fourier Transform Infrared (FTIR) and Vibrating Sample Magnetometer were carried out at room temperature to study the structural and magnetic properties. X-ray patterns revealed the production of a broad single cubic phase with the average particle sizes of ∼12 nm, 5 nm and 8 nm for co-precipitation, normal micelles and reverse micelles methods, respectively. The FTIR measurements between 400 and 4000 cm−1 confirmed the intrinsic cation vibrations of spinel structure for each one of the three methods. Moreover, the average particle sizes were lower than the single domain size (128 nm) and higher than the super-paramagnetic size (2–3 nm) at room temperature. The results revealed that the magnetic properties depend on the particle size and cation distribution, whereas the role of particle size is more significant.
Journal of Magnetism and Magnetic Materials 01/2012; 324(10):1854–1861. · 1.78 Impact Factor
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ABSTRACT: Magnetic ferrofluids (magnetic nanofluids) have received special attention due to their various biomedical applications such as drug delivery and hyperthermia treatment for cancer. The biological applications impose some special requirements. For example, the well-known iron oxide ferrofluids become undesirable because their iron atoms are poorly distinguishable from those of hemoglobin. A conceivable solution is to use mixed-ferrites (MFe2O4 where M=Co, Mn, Ni, Zn) to have a range of magnetic properties. These ferrites have attracted special attention because they save time, and because of their low inherent toxicity, ease of synthesis, physical and chemical stabilities and suitable magnetic properties. Based on the importance of ferrite particles in ferrofluids for hyperthermia treatment, this paper gives a summary on the physical concepts of ferrofluids, hyperthermia principal, magnetic properties and synthesis methods of nanosized ferrites.
Journal of Magnetism and Magnetic Materials 10/2011; 324(6):903–915. · 1.78 Impact Factor
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ABSTRACT: This work presents a systematic investigation on the structural and magnetic properties of Co1−xZnxFe2O4 (0.5<x<0.75) nanoparticles synthesized by the chemical co-precipitation method. The X-ray diffraction analysis, the Fourier Transform Infrared (FTIR) and the Vibrating Sample Magnetometer were carried out at room temperature to study the micro-structural and magnetic properties. The X-ray measurements revealed the production of a broad single cubic phase with the crystallite size within the range of 6–10 nm. The FTIR measurements between 400 and 4000 cm−1 confirmed the intrinsic cation vibrations of the spinel structure. The magnetic measurements show that the saturation magnetization and coercivity decreases by increasing the zinc content. Furthermore, the results reveal that the sample with a chemical composition of Co0.3Zn0.7Fe2O4 exhibits the super-paramagnetic behavior and the Curie point of 97 °C.
Journal of Magnetism and Magnetic Materials.
