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Author(s) |
Vasundhara, K.; Achary, S. N.; Deshpande, S. K.; Babu, P. D.; Meena, S. S.; Tyagi, A. K. (ChD;SSPD)
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Source |
Journal of Applied Physics, 2013. Vol. 113 (19): pp. 194101.1-194101.9 |
ABSTRACT
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In this communication, we report the preparation and properties of nano-CoFe2O4 by gel combustion in presence of KCl and subsequent heat treatments. The products were characterized by X-ray diffraction, Infrared spectroscopy, and
Mossbauer Spectroscopy. Spinel type structure with all Fe in 3+ oxidation states was confirmed from the XRD and
Mossbauer spectroscopy. The average crystallite sizes of the studied samples were about 6 and 50nm. Low temperature magnetic and dielectric properties of the samples were studied by superconducting quantum interference device magnetometry and ac-impedance spectroscopy. The field and temperature dependent magnetization studies indicated superparamagnetic nature for 6 nm sample and ferromagnetic nature for 50nm sample. The temperature-dependent dielectric properties measured over a wide range of frequencies indicated an increasing trend of dielectric permittivity with the decrease in crystallite size. Variable range polaron hopping conduction was observed in both samples. |
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