Low power loss and field-insensitive permeability of Fe-6.5%Si powder cores with manganese oxide-coated particles

作者：Li, Junnan^*; Wang, Xian; Xu, Xiaojun; Gong, Rongzhou; Feng, Zekun; Chen, Yajie; Harris, V. G.

来源：Journal of Applied Physics, 2015, 117(17): 17D518.

DOI：10.1063/1.4919038

• MAGNETIC-PROPERTIES
• MICROSTRUCTURE

Fe-6.5%Si alloy powders coated with manganese oxides using an innovative in situ process were investigated. The in-situ coating of the insulating oxides was realized with a KMnO4 solution by a chemical process. The insulating manganese oxides with mixed valance state were verified by X-ray photoelectron spectroscopy analysis. The thickness of the insulating layer on alloy particles was determined to be in a range of 20-210 nm, depending upon the KMnO4 concentration. The powder core loss and the change in permeability under a DC-bias field were measured at frequencies ranging from 50 to 100 kHz. The experiments indicated that the Fe-6.5%Si powder cores with a 210 nm-thick manganese oxide layer not only showed a low core loss of 459 mW/cm(3) at 100 kHz but also showed a small reduction in permeability (mu(H)/mu(0) = 85% for mu = 42) at a DC-bias field of 80 Oe. This work has defined a novel pathway to realizing low core loss and field-insensitive permeability for Fe-Si powder cores.

• 出版日期2015-5-7
• 单位东北大学; 华中科技大学