| Summary: | Magnetic nanoparticles of Cobalt Ferrite (CoFe2O4) have been
synthesized by co-precipitation method with various synthesis temperatures,
concentration of NaOH and stirring duration. The structural characteristics and
particle�s size of CoFe2O4 were determined by X-ray diffraction (XRD) and
Transmission Electron Microscopy (TEM), it showed that nanoparticles well
crystallized with various grain size which depend on those synthesis parameters.
The grains size estimated using the Scherrer formula were found that the grain
size increased with increasing synthesis temperature, decreasing concentration of
NaOH and decreasing stirring duration. Magnetic properties of CoFe2O4
nanoparticles analized by Vibrating Sample Magnetometer (VSM) showed that
coercive field was decrease with the decreasing of particle size. But it is not for
sample 8,844 and 8,898 nm because of agglomeration effect. The saturation and
remanent magnetization increased with the increasing degree of crystallinity. But
it also depends on presence of α-Fe2O3 phases and their grain size. Based on
magnetic characterization analysis sample have been chosen with temperature
80°C, concentration of NaOH 5 M and stirring duration 120 minutes to modified
with PEG-4000. XRD and TEM analysis showed that modification with PEG-
4000 given increasing degree of crystallinity, decreasing agglomeration and
controlled shape to more spherical. VSM analysis showed that modification with
PEG-4000 given decreasing saturation was predicted because of α-FeO(OH) and
γ-FeO(OH) phases from bonds at interface of CoFe2O4 with PEG-4000 which
shown at XRD and Furrier Transform Infra Red (FTIR) analysis.
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