Nonlinear resistivity in epoxy composites containing Mn‐based ferrite magnetic particles

Abstract

In this study, magnetic particles were employed as nonlinear resistive materials in electric stress grading composites. Epoxy resin films containing either manganese-based ferrite magnetic (Mn-FM) particles or manganese-magnesium-based ferrite magnetic particles were prepared, and the threshold voltages required for these films to exhibit nonlinear resistivity were determined. The sample containing Mn-FM particles having irregular shapes [Mn-FM(i)] at 20 vol % showed the highest nonlinear resistivity. Assessments of the magnetic characteristics of these materials demonstrated a relationship between magnetic flux density and nonlinear resistivity. The magnetic flux density of the Mn-FM(i) composite was the highest among the various specimens, indicating that magnetic flux density may affect nonlinear resistivity.