High performance sintering NiCuZn ferrites absorber sheet for HF application

By using a new and simple blade casting method, a lighter, thinner and higher absorption property sintering NiCuZn ferrite electromagnetic wave absorber sheet was first demonstrated. The electromagnetic wave absorption ability was enhanced by sintered NiCuZn ferrite absorbent. The experiment results reveal that NiCuZn ferrite with thickness 0.1 mm absorber sheet achieves its maximum reflection loss value above 0.5 dB at 13.46 MHz. Meanwhile, the absorption bandwidth is larger than 1 MHz is profitable for wideband electromagnetic wave absorbing. The absorption properties could be controlled by the variation of Nickel content in the spinel lattice and the sintering temperature of NiCuZn ferrites. More homogenous microstructure of SEM micrograph and better crystalline XRD pattern may be responsible for the best absorption ability at 1,150 °C sintering temperature. The absorption properties were also successfully analyzed in this work, which took into account both the frequency at the reflection loss minimum (fr) shift correlated with the value of inductance (L) and impedance (Z) of sintered toroidal cores and the power reflection loss (Γ) depending on ε″, μ″, and εμ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sqrt {\varepsilon \mu }$$\end{document}, where ε and μ are complex relative dielectric permittivity and permeability, respectively, for the attenuation material. The sintering NiCuZn ferrites could merit to be potential candidates as electromagnetic attenuation materials to meet the demands for miniaturization, broader relative bandwidths at HF (3–30 MHz) and beneficial for fabrication of radio frequency identification metal tag.