Fe-based soft magnetic composites coated with NiZn ferrite prepared by a co-precipitation method

• Published in: Journal of magnetism and magnetic materials Vol. 428; pp. 148 - 153
• Main Authors: Peng, Yuandong, Yi, Yi, Li, Liya, Ai, Hengyu, Wang, Xiaoxu, Chen, Lulu
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-04-2017; Elsevier BV
• Subjects: Co-precipitation method; Coating; Cobalt; Composite materials; Coprecipitation; Ferrites; Heat treatment; Insulation; Insulation coating; Iron; Magnetic permeability; Magnetic properties; Magnetism; Nickel; NiZn ferrite; Raman spectroscopy; Scanning electron microscopy; Soft magnetic composite; Spinel; X-ray diffraction; Zinc; Soft magnetic composite; Co-precipitation method; Insulation coating; NiZn ferrite; Magnetic properties
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2016.12.024

Fe powder was coated with NiZn ferrite by a co-precipitation method using chlorate as the raw material. Soft magnetic composites were manufactured via compaction and heat treatment of the coated powder. The coated powder and heat treated powder were analysed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Raman spectroscopy. Their magnetic properties were determined using a Quantum Design-Vibrating Sample Magnetometer (QD-VSM). The composites were analysed with SEM and EDS. The permeability and magnetic loss of the composites were measured with a B-H curve analyzer. The results show that, using the co-precipitation method, the raw precipitate was successfully prepared and coated the pure Fe powder and turned into spinel NiZn ferrite treated at 600℃ for 1h. After heat treatment at 500℃ under air, the insulation coating layer of soft magnetic composite (SMC) was not destroyed and containing Fe, Ni, Zn and oxygen. The permeabilities of the SMC are stable at edge of the 2–200kHz frequency range and the total loss was lower.
Scanning electron microscopy (SEM) images of Fe/(NiZn)Fe2O4 composite powder heated at 600℃ for 1h. [Display omitted]
•Fe particles were coated with (NiZn)Fe2O4 via a co-precipitation and calcined method.•Coating layers were uniform and dense.•The permeabilities of the SMC are stable at edge of the 2–200kHz frequency range.