Magnetopolymer Composites With Soft Magnetic Ferrite Filler

Thanks to their good magnetic properties, NiZn ferrites can be used as the soft magnetic filler in magneto–polymer composites. The ferrites having general composition
${\rm Ni}_{x}{\rm Zn}_{1-x}{\rm Fe}_{2}{\rm O}_{4}$
(
$x=0.30$
, 0.33, 0.36, 0.42, and 0.50) were prepared by means of ceramic method and the magnetic properties, such as initial permeability
$\mu_{i}$
and Curie temperature
$T_{C}$
were investigated. The sample with composition
${\rm Ni}_{0.33}{\rm Zn}_{0.67}{\rm Fe}_{2}{\rm O}_{4}$
having
$\mu_{i}=1316$
and
$T_{C}=95\ ^{\circ}{\rm C}$
was chosen as the filler for magneto–polymer composites. The aim of the work was the study of preparation and properties of magnetic polymer composites based on natural rubber SMR 20 in a wide range of concentrations (0–600 phr). The influence of ferrite content on magnetic, physical–mechanical and rheological properties of prepared composites was investigated. The effect of the concentration of ferrite filler on the complex permeability
$\mu=\mu^{\prime}-j\mu^{\prime\prime}$
of the composites in the frequency range from 10 MHz to 3 GHz as well as the physical–mechanical and rheological properties is evident.