Excessive grain boundary conductivity of spin-spray deposited ferrite/non-magnetic multilayer

Abstract

Magnetic materials with a high self-biased ferromagnetic resonance (FMR) frequency and low electrical conductivity hold great potential for RF/microwave devices. In this work, ferrite film consisting of Fe 3 O 4 (1.2 lm)/photoresist (60 nm)/Fe 3 O 4 (1.2 lm) was deposited at 90 C via spin spray deposition. Broadband impedance imaging with nanometer spatial resolution was recorded by using scanning microwave microscopy. Compared to a reference sample, it turned out that the grain boundary appeared to be more conductive than the grain.

Contribution of Magnetization Mechanisms in MnZn Ferrites with Different Grain Sizes and Sintering Densification

“…For sample 4, as the magnetic permeability contribution from the domain rotation (χ s0 ) is the lowest, its corresponding cut-off frequency ) will increase accordingly. The fitting results confirm these theoretical expectations for both, affirming the credibility of the fitting methodology and outcomes [37][38][39].…”

Phase formation and electrical properties of reactively sputtered Fe1−x O thin films

“…Another approach to understand the difference of electrical conductivity between the thin films and single crystals are the grain boundaries, which exists in the thin films in contrast to the single crystalline reference samples. Reports in literature on Fe 3 O 4 films have shown that the grain boundaries are better electrical conductors than the bulk grains [31,32]. As the crystal structures of both Fe 1−x O and Fe 3 O 4 are similar, one may deduce a similarly better conductivity in grain boundaries for Fe 1−x O films compared to bulk.…”