Effect of morphology of fine-milled powders on the sintering behavior and electromagnetic properties of YIG microwave ferrites

Abstract

In order to meet the application requirements of next-generation microwave devices, a new approach was proposed to reduce microwave dielectric and magnetic losses by optimizing the liquid-to-solid ratio in secondary ball milling process. The experimental results indicated that the variation in the ratio of anhydrous ethanol volume to powder mass strongly influenced the microstructure evolution process of YIG ferrites. At lower liquid-to-solid ratios, a narrow initial particle size distribution promoted the densification of ferrites. This diminished the contribution of porosity-induced linewidth and decreased microwave dielectric loss. The analysis of sintering behavior revealed that the significant abnormal grain growth hindered the densification process at excessively high liquid-to-solid ratios. This phenomenon was also an important reason for the bipolar characteristics observed in dielectric loss.