Preparation of Densified Fine-Grain High-Frequency MnZn Ferrite Using the Cold Sintering Process

Abstract

The densified MnZn ferrite ceramics were prepared using the cold sintering process under pressure, with an acetate ethanol solution used as the transient solvent. The effects of the transient solvent, the pressure and annealing temperature on the density, and the micromorphology and magnetic properties of the sintered MnZn ferrites were studied. The densified MnZn ferrite was obtained using the cold sintering process and its relative density reached up to 85.4%. The transient solvent and high pressure are essential to the cold sintering process for MnZn ferrite. The annealing treatment is indispensable in obtaining the sample with the higher density. The relative density was further increased to 97.2% for the sample annealed at 950 °C for 6 h. The increase in the annealing temperature reduces the power loss at high frequencies.

Special Issue: “Soft Magnetic Materials and Their Applications”

“…Soft ferrites mainly include MnZn ferrites and NiZn ferrites. As a kind of ceramics, ferrites are normally prepared via a sintering process at 900-1450 • C. To prepare soft ferrites with small grain sizes and better high-frequency properties, Ying et al applied cold sintering technique to sinter MnZn ferrites at around 300 • C and obtained a densified, fine-grained, high-frequency MnZn ferrite bulk [1]. The relative density could be increased to 97.2% by annealing the samples at 950 • C for 6 h. Annealing also reduced the power loss at high frequencies.…”

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

“…This necessitates a balance between achieving higher frequencies and maintaining miniaturization. The key challenge in this scenario is mitigating the escalating magnetic losses at high frequencies [16][17][18][19][20].…”