High-frequency MnZn soft magnetic ferrite by engineering grain boundaries with multiple-ion doping

• 作者: Mi Yan Shengbo Yi Xiuyuan Fan Zhenghua Zhang Jiaying Jin Guohua Bai
• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2021,（20）
• 页码范围: 165-170
• 页数: 6页
• 语种: 英文

摘要

MnZn soft magnetic ferrites have been widely utilized in power electronics,owing to the combined merits of high permeability and low energy loss.However,their deployment would result in a drastic increase in power dissipation at ＞3 MHz,thus limiting the scope extent of miniaturization,together with their efficiency.Here,we report a high-performance MnZn ferrite by doping multiple ions (La,Ti,Si,Ca) at grain boundaries,achieving the most optimized power loss of 267 kW/m3 at 5 MHz (10 m T,100 ℃) and initial permeability of 644,which is much better than the previously reported results and commercial products.Such an improvement is attributed to weakened magnetic exchange coupling at grain-boundary regions,associated with a significant transition from the multi-to mono-domain structures,originating physi-cally from large crystallographic mis-orientations (＞25°).The present study bears important significance in understanding the intrinsic correlation between the crystallographic mis-orientation and magnetic domain structure,and provides an alternative way for optimizing high-frequency soft magnetic ferrites.