Study On Preparation Of Fe Doped Barium Titanate Ceramics And Phase Structure And Dielectric Properties

Barium titanate is a typical structure of perovskite ferroelectric materials, because it has high dielectric properties and preparation for all kinds of capacitors in large quantities and also widely used in many electronic devices, materials profession carried out more research in BaTiO3ceramics. The preparation and doping method influences the dielectric properties of barium titanate strongly.High temperature solid state reaction method is the most common of which is also one of the most mature way. The phase structure and dielectric properties of ceramics were characterized by XRD and impedance analyzers.In general, the main work is as follows:(1) Synthesis, Phase Structure and dielectric Properties of barium titanate Ceramics Doped with Fe, Ca.In this work, Ba(1-x)CaxTi(1-y)FeyO3(x=(0,0.01,0.03,0.05,0.1,0.2; y=0.05,0.1) ceramics were prepared by the solid state reaction method, and the dependence of the phase structures and dielectric properties of the Ba(1-x)CaxTi(-1y)FeyO3ceramics on the concentration of Ca dopant were investigated. The phase structures and dielectric properties of the Ba(1-x)CaxTi(1-y)FeyO3ceramics were characterized with the X-ray diffraction (XRD) technique and impedance analyzer, respectively. It was found that the Ca doping promoted the transformation of the phase structure of the Ba(1-x)CaxTi(1-y)FeyO3ceramics from the tetragonal to cubic phase. When the doping concentration of Ca was at x=0.1, the Ba(1-x)CaxTi(1-y)FeyO3ceramics became purely cubic phase. The whole of relative dielectric constant increased and tangent loss of the Ba(1-x)CaxTi(1-y)FeyO3ceramics decreased with the increase of Ca doping.(II) Synthesis, Phase Structure and dielectric Properties of barium titanate Ceramics Doped with F, Sr.In this work, Ba(1-x)SrxTi(1-y)FeyO3=(x=0,0.01,0.03,0.05,0.1,0.2; y=0.05,0.1) ceramics were prepared by the solid state reaction method, and the dependence of the phase structures and dielectric properties of the Ba(1-x)SrxTi(1-y)FeyO3ceramics on the concentration of Sr dopant were investigated. The phase structures and dielectric properties of the Ba(1-x)SrxTi(1-y)FeyO3ceramics were characterized with the X-ray diffraction (XRD) technique and impedance analyzer, respectively. It was found that the Sr doping promoted the transformation of the phase structure of the Ba(1-x)SrxTi(1-y)Fey03ceramics from the tetragonal to cubic phase. The whole of relative dielectric constant decreased but tangent loss of the Ba(1-x)SrxTi(1-y)FeyO3ceramics increased with the increase of Sr doping.(Ⅲ) Synthesis, Phase Structure and dielectric Properties of barium titanate Ceramics Doped with Fe, Y.In this work, Bad(1-x)YxTi(1-y)FeyO3(x=0.0,0.02,0.03,0.05,y=0.05; x=0.01,0.02,0.03,0.05,0.08,0.1; y=0.1) ceramics were prepared by the solid state reaction method, and the dependence of the phase structures and dielectric properties of the Ba(1-x)YxTi(1-y)FeyO3ceramics on the concentration of Y dopant were investigated. The phase structures and dielectric properties of the Ba(1-x)YxTi(1-y)FeyO3ceramics were characterized with the X-ray diffraction (XRD) technique and impedance analyzer, respectively. The results of XRD analysis showed that:when Y doped small, Y3+can fully enter into barium titanate crystal lattice. While Y increases, Y3+can replace both A and B The whole of relative dielectric constant decreased of the Ba(1-x)YxTi0.95Fe0.05O3ceramics but increased of Ba(1-x)YxTi0.9Fe0.1O3ceramics with the increase of Y doping. The tangent loss of the Ba(1-x)YxTi(1-y)FeyO3ceramics all increased with the increase of Y doping.(Ⅳ) Synthesis, Phase Structure and dielectric Properties of barium titanate Ceramics Doped with Ni.In this work, BaTi(1-x)NixO3(x=0,0.01,0.05,0.08,0.1,0.2) ceramics were prepared by the solid state reaction method, and the dependence of the phase structures and dielectric properties of the BaTi(1-x)NixO3ceramics on the concentration of Ni dopant were investigated. The phase structures and dielectric properties of the BaTi(1-x)NixO3ceramics were characterized with the X-ray diffraction (XRD) technique and impedance analyzer, respectively. It was found that the Ni doping promoted the transformation of the phase structure of the BaTi(1-x)NixO3ceramics from the tetragonal to hexagonal phase. When the doping concentration of Ni was at x=0.1, the BaTi(1-x)NixO3ceramics became purely hexagonal phase. With the increase of Ni doping, the lattice constant of the hexagonal BaTi(1-x)NixO3became larger. The whole of relative dielectric constant decreased but tangent loss of the BaTi(1-x)NixO3ceramics decreased first and then increased with the increase of Ni doping.