The aim of the present work is to prepare the
nanoparticles of different ferrites and to study the effect of doping on their
structural and magnetic properties. In the present thesis, we have chosen
nickel ferrite as base matrix which has spinel structure and doped with
nonmagnetic calcium, lead, bismuth, magnesium and aluminium ions. As the
Co-precipitation method is simple, efficient, cost effective in comparison to
other techniques, we have chosen this technique for synthesis of nanoparticles.
We have prepared a series of calcium substituted nickel nanoferrite, lead
substituted nickel nanoferrite, bismuth substituted nickel nanoferrite,
magnesium substituted nickel nanoferrite and aluminium substituted nickel
nanoferrite employed various characterization techniques such as XRD, EDX, SEM,
TEM, FTIR and VSM studies to understand the structural, elemental, morphological,
functional and magnetic properties of the grown nanoparticles. The
calcium substituted nickel ferrite nanoparticles are used in memory device
application based on the squareness ratio. The anisotropy decreases with
increasing Pb2+ concentration which leads to decrease in coercivity.
The value of saturation magnetization increases initially with small
concentration and then decreases with higher concentration. . Substituting
bismuth in nickel ferrites reduces saturation magnetization, coercivity,
remanence and anisotropy constant. The Curie temperature TC decreases with
increasing Al content x, suggesting a decrease in magnetic ordering as the
particle size also decreases.
the light of above mentioned facts, the present thesis aims at:
To prepare rod and
spherical shape nanoparticles of Ca and Pb substituted nickel ferrite by co-precipitation
Ø To study the structural and
morphological and properties of nanoferrite particles using X-ray diffraction,
transmission electron microscope (TEM), scanning electron microscope (SEM), Energy
dispersive X-ray analysis (EDX), Fourier Transform Infrared Spectroscopy
Ø To study magnetic
properties of prepared nanoparticles by using Vibrating Sample Magnetometer
(VSM) at room temperature.
Present Thesis contains Eight Chapters:
I: discusses the general introduction about
magnetism, spinel ferrites and nickel ferrite, review of literature, aim of the
present work and outline of the thesis.
chapter gives brief description of technique used for preparation
nano ferrite and characterization techniques.
III: this chapter presents the results and
discussion of the synthesis, structural and magnetic properties of calcium
doped nickel ferrite samples using XRD, SEM, FESEM, EDX, FTIR and VSM.
IV: this chapter includes the experimental
results of lead doped nickel ferrite by Co-precipitation method and the
prepared samples are characterized by XRD, SEM, TEM,
EDX, FTIR and VSM.
CHAPTER V: this chapter reports study on
the effect of Mg2+ on the structural and magnetic properties using
XRD, SEM, EDX, FTIR and VSM techniques using sol-gel method.
VI: this chapter
deals with the experimental results of bismuth doped nickel ferrite by
Co-precipitation method and discuss the various techniques XRD, SEM, EDX, FTIR
and VSM in detailed manner.
VII: this chapter
gives the experimental results of aluminium doped nickel ferrite nanoparticles
using co-precipitation method and the synthesized samples are subjected to XRD,
SEM, EDX, FTIR and VSM.
CHAPTER VII: this chapter gives the
summary and conclusions of the present work are reported and also suggestion
given here. Suggestions and scope of the future work on the samples studied
have been also included in this chapter.