目的 研究离子掺杂对NiZn铁氧体电磁特性的影响，提高NiZn铁氧体的P波段吸波性能。方法 以NiO、ZnO、Fe2O3、CuO等为原料，采用高温固相反应法，通过球磨、预烧、造粒以及烧结等工艺，制备Cu²⁺掺杂的Ni0.22Zn0.66CuxMn0.04Co0.08–xFe2O4(x=0.04、0.05、0.06、0.07)铁氧体样品。通过XRD、VSM和SEM分别表征样品的晶格特征、磁学特性和微观形貌，利用阻抗分析仪对样品的电磁特性进行测量。结果 Cu²⁺掺杂量的增加引起NiZn铁氧体的A-B超交换作用减弱和磁晶各向异性降低，样品的Ms、Hc和Mr都呈现出减小的趋势。样品的复磁导率与其磁特性关系密切，随着Cu²⁺的增加，实部μ?减小，而虚部μ?增大。此外，Cu²⁺掺杂量的增加对Fe²⁺与Fe³⁺之间的电子迁移率产生影响，使得复介电常数实部ε?增大，而ε?增大的主要原因是Cu²⁺掺杂量的增加导致铁氧体内部产生了晶格缺陷。Cu²⁺的掺杂量对样品的P波段吸波性能影响显著，随着Cu²⁺掺杂量的增加，NiZn铁氧体的阻抗匹配特性明显改善，电磁衰减能力显著提高，这进一步降低了样品的最佳吸波匹配厚度。掺杂量x=0.07的NiZn铁氧体样品，在厚度为6.6 mm时，实现了有效吸波带宽完全覆盖P波段。结论 通过调节Cu²⁺的掺杂量可以调控NiZn铁氧体的P波段吸波性能，增加Cu²⁺掺杂量对于降低样品的P波段吸波匹配厚度有积极作用。

Spinel NiZn ferrite has the advantages of high magnetic permeability, high resistivity, high symmetry of crystal structure and small magnetocrystalline anisotropy (resonant frequency is usually lower than 1 GHz), etc., and it exhibits great potential in the fields of high-performance absorbing materials in P-band for the high electromagnetic loss characteristics. Currently, spinel NiZn ferrite has become one of the main candidates for high-performance absorbing materials in P-band. The work aims to study the effects of ion doping on the electromagnetic characteristics of NiZn ferrite to improve the P-band absorbing performance of NiZn ferrite. The lattice characteristics, magnetic properties and micromorphology of the samples were characterized by XRD, VSM and SEM respectively, and the electromagnetic characteristics of the samples were measured by impedance analyzer. Ni0.22Zn0.66CuxMn0.04Co0.08–xFe2O4 (x=0.04, 0.05, 0.06, 0.07) ferrites doped with Cu2+ ion were synthesized by the high-temperature solid-phase reaction method, which is a typical spinel type face-centered cubic lattice structure with the lattice constant a = 0.839 9 nm. The structure and size of NiZn ferrite particles did not change significantly owing to slight doping of Cu2+ ion was not enough to change the microstructure of the material, but the introduction of Cu2+ ion caused crystal defects to occur inside, and the obvious voids between the particles benefits for the increased the dielectric loss. Based on Debye relaxation polarization, ε? of samples decreased with the increased frequency while ε? increased with that. With the increase of Cu2+ doping, the A-B super exchange effect weakened, which lead to the decrease of Ms. The relative complex permeability was closely related to Ms, therefore, μ‘ decreased and increased with the increase of Cu2+ ions. Due to the existence of domain wall resonance and gyromagnetic spin resonance in the ferrite, the internal magnetic anisotropy field induced the superimposed magnetic resonance of domain wall resonance and gyromagnetic spin resonance, resulting in a negative μ? value of NiZn ferrite at frequency near 1 000 MHz. In addition, due to the existence of the Snoek limit in magnetic materials, the μ? of the material decreased with the increase of frequency. Doping Cu2+ ions had a significant impact on the absorbing properties of Ni0.22Zn0.66CuxMn0.04Co0.08–xFe2O4 ferrites. As the increasing amount of Cu2+ ion doping, the impedance matching characteristics between the material and the air were improved, which weakened the reflectivity of electromagnetic waves at the interface and promoted more electromagnetic waves to enter the material. The doping of Cu2+ ions improved the attenuation ability of ferrites to P-band electromagnetic waves, and enhanced the degree of conversion and dissipation of electromagnetic energy. Due to the improvement of the attenuation ability, the matching thickness of the material broke through the limitation of the quarter-wave resonance mechanism and was significantly reduced. The optimal matching thickness of Ni0.22Zn0.66CuxMn0.04Co0.08–xFe2O4 decreased with the increase of Cu2+ ions, and the effective absorption bandwidth of the sample with x=0.07 completely covered the P-band at a thickness of 6.6 mm. Under the action of enhanced attenuation mechanism, NiZn ferrites doped with Cu2+ ions can achieve excellent absorption performance, and the effective absorption bandwidth covered the P-band at a thinner thickness. It can be seen that the Ni0.22Zn0.66CuxMn0.04Co0.08–xFe2O4 ferrite doped with Cu2+ prepared by high temperature solid-state reaction method can significantly reduce the absorbing matching thickness in P-band, which provides an idea for further research on reducing the thickness of the absorption materials in P-band.