Polycrystalline SrCo_1·2Fe_10·8O₁₉ (SCFO) and SrMn_1·2Fe_10·8O₁₉ (SMFO) samples were prepared by the normal ceramic technique. Powder X-ray diffraction patterns indicated the crystallization in the M-type hexaferrite structure of the samples. X-ray absorption analyses proved Co²⁺ and Mn^3+,4+ ions existing in SCFO and SMFO, respectively. Though Fe³⁺ is dominant in both the compounds, small amounts of Fe²⁺ and Fe⁴⁺ are present in SCFO and SMFO, respectively. Mössbauer spectra analyses also confirmed the dominance of Fe³⁺ in both the samples. Additionally, Fe³⁺ ions in the 12 k, 4f₁, 4f₂, and 2a sites could be attributed to the high-spin state (S = 5/2). A large QS value for the sextet assigned to the 2b site indicated that in this case Fe³⁺ could be in the low-spin state (S = 1/2) or there was the addition of Fe²⁺ (or Fe⁴⁺) when Fe in SrFe₁₂O₁₉ was partially replaced by Co²⁺ (or Mn^3+,4+). The mixture of transition-metal ions with different oxidation states influenced the magnetic properties and microwave shielding ability. At frequencies f = 10–18 GHz, we have found SCFO showing the lowest reflection loss with RL = −11.1 dB at 13.2 GHz and the thickness t = 2.2 mm. With an absorption bandwidth of 0.7 GHz, and about 92% microwave energy being absorbed, SCFO is considered as a potential candidate for microwave shielding applications.

采用普通陶瓷技术制备多晶SrCo _1·2 Fe _10·8 O ₁₉ (SCFO)和SrMn _1·2 Fe _10·8 O ₁₉ (SMFO)样品。粉末 X 射线衍射图表明样品在 M 型六铁氧体结构中结晶。X 射线吸收分析证明 Co ²⁺和 Mn ^3+,4+离子分别存在于 SCFO 和 SMFO 中。尽管 Fe ³⁺在两种化合物中占主导地位，但SCFO 和 SMFO 中分别存在少量 Fe ²⁺和 Fe ⁴⁺。穆斯堡尔谱分析也证实了 Fe ³⁺的主导地位在两个样本中。此外，12 k、4f ₁、4f ₂和2a 位点中的Fe ³⁺离子可归因于高自旋状态（S  = 5/2）。分配给 2b 位点的六重体的大QS值表明，在这种情况下，Fe ³⁺可能处于低自旋状态（S  = 1/2），或者添加了 Fe ²⁺（或 Fe ⁴⁺）当 SrFe ₁₂ O _{19 中的}Fe被 Co ²⁺ (或 Mn ^3+,4+）。不同氧化态的过渡金属离子的混合影响了磁性能和微波屏蔽能力。在频率f  = 10–18 GHz 时，我们发现 SCFO 显示最低反射损耗， 在 13.2 GHz 和厚度t  = 2.2 mm时RL = -11.1 dB 。SCFO 的吸收带宽为 0.7 GHz，吸收了约 92% 的微波能量，被认为是微波屏蔽应用的潜在候选者。