Abstract:
Stoichiometric Ni-Zn ferrite samples with and without dopant iue prepared with
ceramic method and sintered at different temperatures. The dopants, used in this work
are LilO, CaO, CrlO) and COlO). For characterization and determination of lattice
parameters, X-ray diffraction is carried out and for microstructural study, optical
microscopy is used. For the understanding of the magnetic properties of the samples as
modified by compositional change, doping and heat treatment, Curie temperature
measurements, magnetization measurements and permeability measurements are
performed.
X-ray diffraction results indicate that, samples are in good crystalline form. The
Curie temperature measurements show that, with increasing amount of Znl+ Curie
temperature decreases, but dopants appear to have little effect on this ordering
temperature. The magnetization measurements reveal that the use of Li20, CaO and
Cr20) increases the saturation magnetization initially, but with the increase of these
dopants, there is a decrease in the value of saturation mab'lletization. In the case of
C020), however, the saturation magnetization decreases with the addition of C020) all
the way. From the permeability measurements, it is observed that samples with higher
sintering temperature have higher permeability and dopants have apreciable effect on the
permeability. Loss factors and quality factors are also determined which show
compositional dependence to some extent. The experimental results of the permeability
measurements are interpreted in terms of coherent and incoherent domain wall
movements. It has_been found that the samples Nio) ZIIo1Fe204with 0.5% mole Li20
dopant has the best composition for higher permeability. The microstructural study
reveals that, as the sintering temperature is increased the grain size is increased
accordingly.
