Preparation and magnetic properties of silane modified Ni-Zn ferrite and its epoxy composites

Ni-Zn ferrite/epoxy composites were investigated for embedded inductors. Ni-Zn ferrite powder was prepared by a chemical coprecipitation method, and then modified with γ-glycidoxypropyl trimethoxysilane (KH-560). The unmodified ferrite was characterized by a powder X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The XRD curve showed that the ferrite was typical spinel structure, and the measuring result of the VSM indicated that the initial permeability of the ferrite was about 1225.03. The magnetic epoxy composites were respectively fabricated by mixing the modified or unmodified ferrite and epoxy resin. The composites made from the modified-ferrite exhibited better dispersion than that from the unmodified. Magnetic properties of composites were measured by Agilent E 4991 A. The results showed that the permeability of the epoxy composite was rising from 1.4 to 2.1 with the mass fraction of the ferrite increasing in the composite from 30% ~ 70%, and magnetic loss was low.