Improvements of magnetic performances for carbonyl iron soft magnetic composites (CI-SMCs) induced by Mn-based phosphating coating

作者：He, YiHai; Li, GuanBiao; Yang, Sheng; Tian, Mengyuan; Xu, Jia; Gennadii, Govor; Olga, Demidenko; Wu, ZhaoYang^*; Liu, Xin^*; Wang, Jian^*

来源：Journal of Alloys and Compounds, 2023, 958: 170498.

DOI：10.1016/j.jallcom.2023.170498

• Soft magnetic composites
• Mn-based phosphate
• Double-exchange effect
• Magnetic performance

A novel soft magnetic composites coated with Mn-based phosphate was successfully prepared in this work. Microstructural analysis showed that the hybrid layers coated on the surface of carbonyl iron powder were composed of Mn0.43Fe2.57O4, FeMnO3, and Fe7(P2O7)4. The hysteresis loss of carbonyl iron soft magnetic composites was significantly improved due to the grain growth caused by the introduction of Mn. Meanwhile, the double-exchange effect between Mn4+and Mn3+ promoted the transformation from anti-ferromagnetic to ferromagnetic for FeMnO3 and Mn3+ oxides so as to increased the saturation magneti-zation and permeability. Compared with the carbonyl iron soft magnetic composites coated with phosphate, the permeability increased from 49 to 87 and the core loss decreased from 501.9 to 361.3 kW/m3 for the composites coated with Mn-based phosphate. Notably, the magnetic performance (principally permeability) of carbonyl iron soft magnetic composites could be optimized by employing the Mn-based phosphate coating.