The Electromagnetic Properties Of Multi-phase M-type Barium Ferrite-based Absorption Material

Mn/Ti-doped barium ferrites(Ba(Mn_0.5Ti_0.5)_xFe_12-xO₁₉)were synthesized by solid state reaction route.The electromagnetic?EM?parameters of Ba(Mn_0.5Ti_0.5)_xFe_12-xO₁₉9 are improved.The peaks in imaginary permittivity and permeability are attributed to strong relaxation behavior and ferromagnetic resonance,respectively.The enhanced resonance peaks are observed in multi-band of C,X and Ku bands,and is almost 10 times higher than that of pure barium ferrites?BaM?.Moreover,the relaxation behaviors in different band are beneficial to microwave absorption.The Ba(Mn_0.5Ti_0.5)_x Fe_12-xO₁₉9 has a tunable effect on EM property.Multi-region microwave absorption is found to supply a wide horizon for barium ferrite optimization.The maximum absorption value of the Ba(Mn_0.5Ti_0.5)_xFe_12-xO₁₉is^-31 dB with thickness of 2.3 mm,as well as the bandwidth within-10 dB almost covers⁵ GHz in investigated frequency from 2 to 18 GHz.These results indicate that Ba(Mn_0.5Ti_0.5)_x Fe_12-x2-x O₁₉9 is a better candidate in the fields of microwave absorption and microwave functional devices in broad frequency band.We investigated synergic microwave absorption performance of BiFeO₃-Ba?MnTi?_2.5Fe₇O₁₉9 composites synthesized by solid mixing method.XRD pattern and SEM analysis indicate that blessed Ba?MnTi?_2.5Fe₇O₁₉9 give rise to considerable hetero-phase boundary.Accordingly,The minimum reflection loss of the composites with volume ratio of 1.5:1 reaches-48 dB,which is almost two times of that of BiFeO₃.The improved microwave absorption could be ascribed to electromagnetic match between the high dielectric loss and increased magnetic loss as a consequence of dielectric multi-relaxation behavior and strong ferromagnetic romance,respectively.These results suggest that Ba?MnTi?_2.5Fe₇O₁₉-blessed BiFeO₃ could be a promising attenuation materials in imaging,healthcare,information safety and military fields.Ba?MnTi?_2.5Fe₇O₁₉-SiC composite material prepared by solid state reaction route.When the volume percentage is 15%,the minimum reflection loss is–42 dB.Which more higher than that of SiC or Ba?MnTi?_2.5Fe₇O₁₉.The enhanced microwave attenuation is attributed to the improved electromagnetic properties and electromagnetic matching,the reflection of electromagnetic wave is less and enter into inner material then absorption.The result verifies the idea that composite with dielectric and magnetic materials leads to a combination of dielectric and magnetic properties and achieves electromagnetic matching,finally enhances the microwave absorption.The composite of Ba?MnTi?_2.5Fe₇O₁₉-SiC not only develops a new efficient microwave absorbing material,more importantly provides a way of designing microwave absorbing materials.