Anantharaman, M R; Asha, Mary John; Mathew, George; Swapna, Nair S; Joy, P A(Elsevier, October 10, 2005)
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Abstract:
Nanoparticles of nickel ferrite have been synthesized by the sol–gel method and the effect of grain size on its structural and magnetic
properties have been studied in detail. X-ray diffraction (XRD) studies revealed that all the samples are single phasic possessing the
inverse spinel structure. Grain size of the sol–gel synthesized powders has been determined from the XRD data and the strain graph. A
grain size of 9 nm was observed for the as prepared powders of NiFe2O4 obtained through the sol–gel method. It was also observed that
strain was induced during the firing process. Magnetization measurements have been carried out on all the samples prepared in the
present series. It was found that the specific magnetization of the nanosized NiFe2O4 powders was lower than that of the corresponding
coarse-grained counterparts and decreased with a decrease in grain size. The coercivity of the sol–gel synthesized NiFe2O4 nanoparticles
attained a maximum value when the grain size was 15nm and then decreased as the grain size was increased further.
Description:
Journal of Magnetism and Magnetic Materials 302 (2006) 190–195
Anantharaman, M R; Muhammad, Abdul Jamal E; Joy, P A; Philip, Kurian(Elsevier, January 3, 2010)
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Abstract:
Nickel nanocomposites were prepared by incorporating nickel nanoparticles in a neoprene matrix according
to a specific recipe for various loadings of nickel particles. The dielectric properties of these composites
were evaluated for different frequencies ranging from 100 kHz to 8MHz at different temperatures from
30 ◦C to 120 ◦C. The dielectric permittivity increases with increase of nickel concentration. Increase in
temperature enhances the permittivity initially, till 40 ◦C and thereafter the permittivity decreases. The
dielectric loss exhibits relaxation peaks and the peaks shift to lower frequencies with increase in volume
fraction of the nickel nanoparticles in the matrix. The evaluation of magnetic and dielectric properties
of these composites suggests that the dielectric permittivity can be tailored by an appropriate loading of
the filler using semi-empirical equations and the magnetic properties vary according to simple mixture
equations
Description:
Materials Chemistry and Physics 121 (2010) 154–160
Anantharaman, M R; Muhammad, Abdul Jamal E; Joy, P A; Philip, Kurian(Springer, December 25, 2009)
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Abstract:
Rubber–nickel nanocomposites were synthesized by incorporating
freshly prepared nanometric nickel particles in two different matrices namely natural
rubber and neoprene rubber according to specific recipes for various loadings of
nano nickel and the cure characteristics of these composites were evaluated. The
maximum torque values register an increase with the increase in loading of nickel in
both composites and this is attributed to the non-interacting nature of nickel
nanoparticles with rubber matrices. The cure time of natural rubber composites
decreases with increase in the content of nickel, and in neoprene rubber cure, time
increases with increase in filler content. In natural rubber, the curing reaction seems
to be activated by the presence of nickel particles. The magnetization studies of the
composites reveal that the magnetic properties of nickel are retained in the composite
samples. The elastic modulus of natural rubber and neoprene rubber are
largely improved by the incorporation of nickel particles