Synthesis and electromagnetic properties of U-type hexaferrites Ba4B2Fe36O60 (B: Co, Ni, Cu)

• Published in: Journal of magnetism and magnetic materials Vol. 325; pp. 63 - 68
• Main Authors: Shannigrahi, S.R., Au, W.Q., Suresh Kumar, V., Liu, L., Yang, Z.H., Cheng, C., Tan, C.K.I., Ramanujan, R.V.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-01-2013; Elsevier
• Subjects: Complex permittivity; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Copper; Diffraction; Domain effects, magnetization curves, and hysteresis; Exact sciences and technology; Magnetic properties; Magnetic properties and materials; Magnetization curves, magnetization reversal, hysteresis, barkhausen and related effects; Microwave absorption; Microwave and radio-frequency interactions (excluding resonances); Nickel; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other interactions of matter with particles and radiation; Physics; Polyethylenes; Saturation (magnetic); Solid state sintering; Spectra; U-type hexaferrite; U-type hexaferrite; Solid state sintering; Microwave absorption; Hexagonal ferrites; Magnetization; Interference; Magnetic field effects; XRD; Magnetic permeability; Sintering; Solid state reaction; Complex permittivity; Codoping; Saturation magnetization
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2012.08.019

Polycrystalline samples of U-type hexaferrites Ba4B2Fe36O60 (B: Co, Ni and Cu) were synthesized using a modified solid state reaction technique. The sintered hexaferrites were tested for their crystalline quality using x-ray diffraction technique and their magnetic properties using the Physical Property Measurement System (PPMS). The individual ferrites were further used as fillers to prepare composites using a polyethylene matrix. The composites were tested for their complex permittivity and permeability spectra and finally reflection loss spectra were derived from these results. Among the studied composites, lowest and highest values of saturation magnetization were 25 and 35emu/g, respectively, for the Cu doped hexaferrites and the Co doped hexaferrites. All the studied composites demonstrated microwave absorption property, which was tunable by manipulating the sample thickness. Co-doped composites offered the highest absorption (∼98%) and were found the most suitable to suppress electromagnetic interference.
► Synthesis of U-type hexaferrites: Ba4B2Fe36O60 (B: Co, Ni, Cu) using modified solid state reaction process. ► Developed composites using ferrite fillers and a polyethylene matrix. ► Characterization of electromagnetic properties of the composites. ► Cobalt-doped composites have the highest electromagnetic absorption (∼98%).