Co substituted BaFe ₁₂ O ₁₉ ceramics with enhanced magnetic resonance behavior and microwave absorption properties in 2.6 – 18 GHz

BaFe _12-x Co _x O ₁₉ (BFCO, x ≤ 0.4) ceramics with superior magnetic and electromagnetic (EM) properties were prepared using Co ³⁺ substituted BaFe ₁₂ O ₁₉ (BFO) in 2.6–18 GHz. Compared with the ceramics without Co ³⁺ , the incorporation of 40 mol% Co ³⁺ enhances magnetic properties; the saturation magnetization (M _S ) is improved by about 55.6 emu·g ⁻¹ due to the variety of magnetocrystalline anisotropy. The resonance behaviors of complex permeability are observed and resonance frequency shifts to lower frequency range from 6 to 3 GHz. The minimum reflection loss (RL) of −32.1 dB (<−10 dB) is obtained at 11.2 GHz in 8.5–13.5 GHz at 2.0 mm thickness in the sample with x = 0.4, which suggests that such ceramics is highly promising as effective microwave absorbers for EM applications.