1. Sol-Gel Fabricated CoFe2O4/SiO2 Nanocomposites: Synthesis and Magnetic Properties.
- Author
-
Vejpravová, Jana, Plocek, Jiří, Nižňanský, Daniel, Hutlová, Alžbĕta, Rehspringer, Jean L., and Sechovský, Vladimir
- Subjects
- *
MAGNETISM , *NANOPARTICLES , *MAGNETIC properties , *SILICON oxide , *GELATION , *SPECTRUM analysis - Abstract
Well-defined CoFe2 O4 nanoparticles embedded in an amorphous SiO2 matrix have been synthesized by a sol-gel method, characterized and investigated by Mössbauer spectroscopy and magnetic properties measurements. The mean particle size increases from 3 to 15 nm consistently with the temperature of the subsequent annealing, which varied from 800°C to 1100°C, respectively. The composites exhibit superparamagnetic behavior with the blocking temperature TB increasing with the mean particle size from 80 to 350 K, respectively. Sufficiently high value of Hc ∼ 2.5 T (at 2 K) has been observed for the sample annealed at 1100°C. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF