Resistive magnetodielectric property of polycrystalline γ-Fe2O3

Abstract

We have systematically investigated the magnetodielectric property of polycrystalline γ-Fe2O3. The dielectric constants of γ-Fe2O3 seem to follow the Maxwell-Wagner model, i.e., their large enhancement and strong temperature and frequency dependences. Positive magnetodielectric property is observed with negative magnetoresistance, at least above 180K. The value of magnetodielectric effect is maximized at the specific frequency, which is inversely proportional to resistivity. Based on the Maxwell-Wagner model and the magnetoresistance, we can reproduce the magnetodielectric effect of γ-Fe2O3.