Sol-gel auto combustion synthesis of CoFe2O4/1-methyl-2-pyrrolidone nanocomposite: Its magnetic characterization


KURTAN Ü. , Topkaya R., Esir S., Baykal A.

CERAMICS INTERNATIONAL, vol.39, no.6, pp.6407-6413, 2013 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 39 Issue: 6
  • Publication Date: 2013
  • Doi Number: 10.1016/j.ceramint.2013.01.067
  • Title of Journal : CERAMICS INTERNATIONAL
  • Page Numbers: pp.6407-6413
  • Keywords: 1-Methyl-2-pyrrolidone, CoFe2O4, Saturation magnetization, Magnetic nanomaterials, COFE2O4

Abstract

A magnetic nanocomposite was generated by the sol-gel auto-combustion method in the presence of 1-methyl-2-pyrrolidone, a functional solvent. The temperature-dependent magnetic properties of the CoFe2O4 nanoparticles have been extensively studied in the temperature range of 10-400 K and magnetic fields up to 80 kOe. Zero field cooled (ZFC) and field cooled (FC) curves indicate that the blocking temperature (T-B) of the CoFe2O4 nanoparticles is above 400 K. It was found from M-H curves that the low temperature saturation magnetization values are higher than bulk value of CoFe2O4. The saturation magnetization (M-s), remanence magnetization (M-r), reduced remanent magnetization (M-r/M-s) and coercive field (H-c) values decrease with increasing temperature. The M-r/M-s value of 0.75 at 10 K indicates that the CoFe2O4 nanoparticles used in this work have, as expected, cubic magnetocrystalline anisotropy according to the Stoner-Wohlfarth model. T-1/2 dependence of the coercive field was observed in the temperature range of 10-400 K according to Kneller's law. The extrapolated T-B and the zero-temperature coercive field values calculated according to Kneller's law are almost 427 K and 13.2 kOe, respectively. The room temperature H-c value is higher than that of the previously reported room temperature bulk values. The effective magnetic anisotropy constant (K-eff) was calculated as about 0.23 x 10(6) erg/cm(3) which is lower than that of the bulk value obtained due to disordered surface spins. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.