| Manganese-zinc-ferrous ferrltes of estimated structural compositions
Znu16Mn0•706Feo.078Fe20 4 and Zno.197Mno.,83 Fe o.uoFez04
were ferrltized at 1120° and 1()90°C using air atmosphere during
heating and soaking periods and argon atmosphere during coolIng.
This ferrltlzed powder after grinding to= 5 11m was pressed
into toroid and cylindrical pellets. Slnterlng of shapes was done
In air at temperatures of 1220° and 1250°C and for a soaking
periods of 6 hours, while the heating and cooling were done in air
and argon respectively. Lattice parameters were determined b~
the X-ray method; the values ranged between 4.487 and 4.497 A
for materials ferrltlzed under different conditions. Real and
Imaginary parts of complex permeability, 11 and 11 and quality
factor Q were determined In the frequency range 100-2000 kHz
using Impedance bridge on toroidal samples. The values varied In
the range 370-648 (for !l), 30-54 (for !l") and 7-16 (for Q) at 100
kHz. The permeability at 100kHz range was 373-651 against the
expected value or 1500 for such applications. The d.c. resistivity
was determined using complex Impedance analysis and values
ranged between 276 and 5762 ohm-em as compared to values of
= 700 ohm-em reported in the literature. The values of saturation
magnetization (crs) ranged between 96 and 108 emu/gm and
Curle temperatures for compositions 1 and 2 were found to be
245° and 281°C respectively. |
