High-frequency magnetic properties of ferrite particulate films

Abstract Ni–Zn ferrite particulate films fabricated by two room-temperature colloidal processing methods are characterized through high-frequency magnetization measurements. The particles for the colloidal solution are synthesized by coprecipitatation, affording particles 5–20 nm in size. The films prepared from the solution are shown to consist of 15–40 nm particles in a densely packed arrangement. The film prepared by electrophoretic deposition (EPD) is 12 μm thick with a comparatively smooth surface. Measurements of the frequency dependence of complex permeability for the films reveal an external bias field dependence and high magnetic resonance frequency (1 GHz), despite the films being isotropic.