Abstract CoRu-substituted BaM hexaferrites, with additives of Bi2O3, demonstrate low losses and high permeability above 1 GHz. The RuCo- and BiRuCo-doped BaM ferrites were prepared by conventional solid-state reaction methods. Magnetic spectra indicate that there were two peaks in the imaginary part of the permeability spectra which originate from domain wall motion and spin rotation. Compared to the RuCo-BaM sample, BiRuCo-doped BaM samples exhibit slight decreases in permeability (~2.9), but the magnetic loss tangents decrease markedly by 47% to ~0.05 at 1 GHz while retaining a low magnetic loss ~0.1 up to 1.5 GHz. From fitting to experimental data, it’s clear that the reduction of magnetic loss stems predominantly from a suppressed domain wall damping due to the introduction of Bi2O3. It is demonstrated that Bi2O3 can effectively control the microstructure of polycrystalline ferrites, and in turn tailor the contribution of domain wall resonance or spin rotation to permeability and magnetic loss. The results are valuable to the engineering of ferrite materials for use in the miniaturization of wide band microwave antenna at operating frequencies up to 1 GHz.

中文翻译：

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用于微波器件小型化的平面 BaM 六铁氧体中抑制畴壁阻尼

摘要 CoRu 取代的 BaM 六铁氧体与 Bi2O3 添加剂在 1 GHz 以上表现出低损耗和高磁导率。RuCo 和 BiRuCo 掺杂的 BaM 铁氧体是通过传统的固态反应方法制备的。磁谱表明磁导率谱的虚部有两个峰值，分别来自畴壁运动和自旋旋转。与 RuCo-BaM 样品相比，BiRuCo 掺杂的 BaM 样品的磁导率略有下降（~2.9），但磁损耗正切在 1 GHz 时显着降低 47% 至~0.05，同时保持低磁损耗~0.1 至 1.5吉赫兹。从拟合到实验数据，很明显，磁损耗的减少主要源于由于引入 Bi2O3 抑制畴壁阻尼。结果表明，Bi2O3 可以有效地控制多晶铁氧体的微观结构，进而调整畴壁共振或自旋旋转对磁导率和磁损耗的贡献。该结果对铁氧体材料的工程设计非常有价值，可用于工作频率高达 1 GHz 的宽带微波天线的小型化。