Excellent microwave absorption performance of zinc-doped SrFe12O19 hexaferrite and detailed loss mechanism

In this work, the SrFe_12–xZn_xO₁₉ (Zn-SrM, x = 0, 0.1, 0.4, and 1.0) samples were fabricated using a combination of ball milling and heat treatment methods, which was simple and low-cost. Interestingly, the Zn-SrM samples exhibited great microwave absorption performances with an absorption rate of more than 99.99% and very thin thicknesses. The x = 0.1 sample could reach an excellent RL value of −40.08 dB at f = 17.88 GHz for a thickness of 1.45 mm. The x = 0.4 sample achieved a great RL value of −42.51 dB at 17.86 GHz and an EAB value of 1.29 GHz for t = 1.50 mm. With a thickness of 5.1 mm, the x = 1.0 sample could achieve a great RL value of −51.20 dB and an EAB value of 1.58 GHz. This microwave absorption performance, low cost, and simplicity of fabrication could confirm that Zn-SrM samples could be used as high-efficiency MAMs. The great microwave dissipating characteristics could be attributed to the high values of imaginary parts of complex permeability and complex permittivity leading to the high loss tangent, high degree of impedance matching, high values of attenuation constant and conductivity, suitable values of eddy current factor, and large numbers of semicircles in their Cole-Cole plots.