Microstructure and microwave electromagnetic properties of Dy3+-doped W-type hexaferrites

Abstract

Ba(subscript 1-x)OY(subscript x)Co2Fe16O27 (x=0.00, 0.05, 0.10, 0.15, and 0.20) was prepared by the solid-state method. The phase structure was studied using powder X-ray diffraction (XRD), the electromagnetic properties were measured, and the reflection loss of Oy(superscript 3+)-doped ferrite material was calculated using electromagnetic parameters by the transmission line theory. All XRD patterns showed the single phase of the magnetoplumbite barium ferrite without other intermediate phase when x≤0.15. The values of e' and e” increased slightly with Dy(superscript 3+) ions doping. The values of μ” and μ' were improved with Dy(superscript 3+) doping, exhibiting excellent microwave magnetic performance. The reasons have also been discussed using the electromagnetic theory. Dy substitution could increase microwave-absorbing performance and broaden frequency band (reflection loss (RL) ＜ -10 dB), and the absorbing peak shifted to high-frequency position. When x=0.2, ferrite layer exhibited the most excellent microwave-absorbing performance at a thin matching thickness of 1.5 mm. The peak value of RL was around -15 dB, and the frequency band (RL＜-10 dB) was about 7 GHz (from 8 to 15 GHz).