Author/Authors :
Ana Cristina F. M. Costa، نويسنده , , Ma´ rcio R. Morelli، نويسنده , ,
Ruth H. G. A. Kiminami، نويسنده ,
Abstract :
An investigation was made of samples
having a chemical formula of Ni1–xZnxFe2O4, where
x = 0.3, 0.5 and 0.7. The samples were prepared by the
reaction combustion synthesis method and sintered at
1,200 C/2 h in a static air atmosphere. The influence
of the Zn concentration on the relative density,
microstructure and magnetic properties of the samples
was studied. X-ray diffraction, scanning electron
microscopy and magnetic hysteresis loop tracer were
used to analyze the compositions. The samples were
found to have a spinel cubic structure, sintered density
of 92.9%–98.8% of the corresponding X-ray density,
homogeneous microstructure with grain size ranging
from 1.37 to 3.36 lm, maximum flux density of 0.16–
0.35 T, field coercivity ranging from 17 to 168 A/m,
and loss hysteresis of 1.5–105 W/kg. Increased grain
growth, with fine pores inside the grains, was found to
occur as the Zn concentration increased. The overall
findings are discussed here in light of the existing
understanding of these systems.
