Abstract Cation-substituted magnetite (MFe2O4, M = Mg, Zn, Mn) were prepared by a facile oxidation-precipitation process in an oxygen-free environment without autoclaves. By XRD, TEM, FESEM and EDS mapping analysis, the as-prepared MFe2O4 are characterized to be polycrystalline nanoparticles with spinel structures and regulated M/Fe ratios. Their electromagnetic properties are strongly dependent on the substitution of M2+. MnFe2O4 has higher saturation magnetization and increased coercivity in contrast to MgFe2O4 and ZnFe2O4. At the optimum absorbent thickness, ZnFe2O4 achieves a minimum reflection loss of −23.4 dB around 17.9 GHz, while MnFe2O4 exhibits a broad effective absorbing bandwidth covering 6.4 GHz in medium frequency ranges. The intense magnetic loss for MnFe2O4 and high dielectric loss together with effective electromagnetic impedance matching for ZnFe2O4 should be responsible for their enhanced microwave absorption performance.

中文翻译：

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通过简易氧化沉淀法制备的尖晶石 MFe2O4 (M=Mg, Mn, Zn) 纳米粒子的表征和微波吸收

摘要 阳离子取代磁铁矿（MFe2O4, M = Mg, Zn, Mn）是在无高压釜的无氧环境中通过简便的氧化-沉淀工艺制备的。通过 XRD、TEM、FESEM 和 EDS 映射分析，所制备的 MFe2O4 被表征为具有尖晶石结构和调节 M/Fe 比的多晶纳米粒子。它们的电磁特性强烈依赖于 M2+ 的取代。与 MgFe2O4 和 ZnFe2O4 相比，MnFe2O4 具有更高的饱和磁化强度和更高的矫顽力。在最佳吸收剂厚度下，ZnFe2O4 在 17.9 GHz 附近实现 -23.4 dB 的最小反射损耗，而 MnFe2O4 在中频范围内表现出覆盖 6.4 GHz 的宽有效吸收带宽。