Study On The Preparation And Properties Of Ru Doped ZnFe₂O₄ And Co-Ru Co-doped BaFe₁₂O₁₉

In this paper,the influence of Ru doping on the formation,optical characteristics and absorbing properties of spinel ferrite ZnFe₂O₄and Co-Ru doping on the formation,optical characteristics,magnetic properties and absorbing properties of magneto plumbite type ferrite BaFe₁₂O₁₉have been studied.The following results were obtained:Single-phase ZnFe_2-xRu_xO₄（x=0,0.1,0.3,0.5,0.6）was synthesized by solid-phase method.According to the comparison of XRD cards,the doping causes lattice distortion,the diffraction peak shows blue-shifts and the lattice constant a value increases.Moreover,the diffraction peak becomes sharp,the lattice size expands,and the grain grows well,which is confirmed by the SEM image.FT-IR spectra showed that the substitution of Ru⁴⁺forFe³⁺changed the ion distribution at the a site of the tetrahedron in the spinel lattice,and the entry of Ru⁴⁺at the A site shortened the bond length and increased the bond energy.UV-Vis spectra showed that the band gap of ZnFe_2-xRu_xO₄decreased from 2.19 e V at x=0 to 1.35 e V at x=0.6,which increased the photocatalytic activity of the material.After electromagnetic parameter analysis,it is found that both dielectric resonance and magnetic resonance affect the absorbing performance of the material,and the obvious Cole-Cole curve of ZnFe_2-xRu_xO₄on theε’-ε’’complex plane is presented.The optimal reflection loss of x=0.5 sample is-11.3 d B,and the absorption bandwidth is 9.5-15.3 GHz.With the increase of doping amount,the absorption capacity of the material decreases,but the absorption bandwidth is improved.The sample BaFe_12-xCo_xRu_xO₁₉was synthesized by solid phase method（x=0,0.1,0.3,0.5,0.7,0.9）.After XRD fitting,it was found that the samples were all single phase.Co²⁺-Ru⁴⁺co-doping causes lattice distortion of barium ferrite,and the lattice constant a increases and c decreases in general.Co²⁺（r=0.72?）enters the octahedral position,while Ru⁴⁺（r=0.62?）enters the tetrahedron and hexahedron position.The UV-Vis spectra showed that the band gap width of the material decreased from 1.52e V（x=0.1）to 1.31e V（x=0.9）.The results indicate that CO²⁺-Ru⁴⁺co-doping is beneficial to the formation of hole-electron pairs and improves the optical properties of the materials.After magnetic analysis,it was found that at T=300 K,the coercivity Hc decreased from the maximum value of 1.3001 KOe at x=0.1 to the minimum value of 0.0811KOe at x=0.5,The saturation magnetization M_sreaches the maximum value of 62.0054 emu·g^-1at x=0.3,and the barium ferrite changes from ferromagnetism to soft magnetism.The material exhibits good NMR at 2-18GHz,which is conducive to microwave absorption.After doping,the reflection loss of the samples are all less than-10 d B.When the impurity material x=0.5 and the thickness is 3.7 mm,the best reflection loss RL value is-31.5 d B at 9.7 GHz,and the absorbing range almost covers the whole wave band.