We report the temperature and frequency dependence impedance spectroscopy of(1-x)(Bi_(0.5)Na_(0.5))TiO_(3-x)BaTiO_(3)(abbreviated as BNT-BT)ceramics with 0≤x≤0.07 prepared by conventional solid-state route.X-ray dif...We report the temperature and frequency dependence impedance spectroscopy of(1-x)(Bi_(0.5)Na_(0.5))TiO_(3-x)BaTiO_(3)(abbreviated as BNT-BT)ceramics with 0≤x≤0.07 prepared by conventional solid-state route.X-ray diffraction analysis indicated that a solid solution is formed when BaTiO_(3)diffuses into the(Bi_(0.5)Na_(0.5))TiO_(3)lattice and a morphotropic phase boundary between rhombohedral and tetragonal locates at x=0.07.The microstructure indicated that the grain size reduces and the shape changes from rectangular to quasi-spherical with increase in BaTiO_(3)content.Complex Impedance Spectroscopy analysis suggested the presence of temperature-dependent relaxation process in the materials.The modulus mechanism indicated the nonDebye type of conductivity relaxation in the materials,which is supported by impedance data.The activation energies have been calculated from impedance,electric modulus studies and dc conductivity which suggests that the conductions are ionic in nature.The activation energy increases with increase of BT content up to x=0.05 and decreases at x=0.07 which also indicates the presence of morphotropic phase boundary at x=0.07.展开更多
文摘We report the temperature and frequency dependence impedance spectroscopy of(1-x)(Bi_(0.5)Na_(0.5))TiO_(3-x)BaTiO_(3)(abbreviated as BNT-BT)ceramics with 0≤x≤0.07 prepared by conventional solid-state route.X-ray diffraction analysis indicated that a solid solution is formed when BaTiO_(3)diffuses into the(Bi_(0.5)Na_(0.5))TiO_(3)lattice and a morphotropic phase boundary between rhombohedral and tetragonal locates at x=0.07.The microstructure indicated that the grain size reduces and the shape changes from rectangular to quasi-spherical with increase in BaTiO_(3)content.Complex Impedance Spectroscopy analysis suggested the presence of temperature-dependent relaxation process in the materials.The modulus mechanism indicated the nonDebye type of conductivity relaxation in the materials,which is supported by impedance data.The activation energies have been calculated from impedance,electric modulus studies and dc conductivity which suggests that the conductions are ionic in nature.The activation energy increases with increase of BT content up to x=0.05 and decreases at x=0.07 which also indicates the presence of morphotropic phase boundary at x=0.07.
