Study of DC conductivity and relative magnetic permeability of nanoparticle NiZnFe2O4/PPy composites

The DC conductivity and the relative magnetic permeability have been measured as functions of temperature for five powder samples of nanoparticle ferrites (NixZn1−xFe2O4; x=0, 0.25, 0.5, 0.75 and 1), a pure polypyrrole (PPy) powder sample and many composite samples prepared by mixing different ratios of the ferrites to PPy. By comparing the results it is found that there is an obvious increase in DC conductivity of the ferrite/PPy composite samples compared to the corresponding pure ferrite samples, whereas compared to the pure PPy sample there is a decrease in DC conductivity. On the contrary, the magnetic permeability of the composites is higher than that of the pure PPy sample and lower than that of the pure ferrite samples as was expected.

Research highlight
► This research reports a comparative study of both the DC electrical conductivity and the magnetic permeability of three groups of materials.
► The investigated groups include ferrites (NixZn1−xFe2O4; with varying x), polypyrrole (PPy) and composite samples of (NixZn1−xFe2O4/PPy) with different weight ratios.
► Such a study had not been reported before despite it may be of considerable importance for material designers for practical applications.