Acid doped Polyaniline(PANI)due to their increased electrical conductivity,are considered to be the most promising conducting filler materials.Hence,the present study,reports the synthesis of the PANI followed by acid...Acid doped Polyaniline(PANI)due to their increased electrical conductivity,are considered to be the most promising conducting filler materials.Hence,the present study,reports the synthesis of the PANI followed by acid doping,electrical conductivity and dielectric properties measurements of H2SO4;HCl and(Conc.HCl+NaNO2mixture)doped PANI.In order to know the effect of acetone washing on the electrical properties of acid doped PANI samples,the electrical properties of the non-acetone washed acid doped PANI samples are compared with that of their acetone washed counterparts.The PANI salt was prepared by conventional route using aniline hydrochloride and ammonium persulphate as an oxidant.PANI salt was subjected to 0.5M NaOH to form PANI base,which was further doped separately with H2SO4;HCl and(Conc.HCl+NaNO2mixture)respectively followed by acetone washing.A comparative electrical conductivity study between the acetone washed and unwashed PANI salt and H2SO4,HCl and Conc.HCl+NaNO2 mixture doped PANI were characterized by dielectric and impedance study.展开更多
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
Aurivillius type compound BaBi_(4)Ti_(4)O_(15)(BBT)ceramic was prepared by solid state reaction route and its electrical properties were studied.X-ray diffraction(XRD)pattern showed orthorhombic structure with space g...Aurivillius type compound BaBi_(4)Ti_(4)O_(15)(BBT)ceramic was prepared by solid state reaction route and its electrical properties were studied.X-ray diffraction(XRD)pattern showed orthorhombic structure with space group A21am confirming it to be an m=4 member of the Aurivillius oxide.The scanning electron microscope of the sintered pellet showed a plate-like morphology of grains which is a characteristic feature of the Aurivillius compounds.The temperature and frequency dependence dielectric study showed a shifting of transition temperature with frequency indicating relaxor type behavior in the material.The diffuseness parameter(γ)established the relaxor nature and it was attributed to the A-site cationic disorder.The dielectric relaxation obeyed the VogelFulcher(VF)relation and various parameters like activation energy for relaxation,freezing temperature,relaxation frequency were determined after nonlinear curve fitting.The temperature dependence of dielectric constant at temperatures much higher and lower than Tm was analyzed by two exponential functions,which gives an idea about the production of polar clusters at high temperature and the distribution of freezing temperatures at lower temperature.Various other associated parameters were calculated by nonlinear curve fitting and their significance has been explained.展开更多
文摘Acid doped Polyaniline(PANI)due to their increased electrical conductivity,are considered to be the most promising conducting filler materials.Hence,the present study,reports the synthesis of the PANI followed by acid doping,electrical conductivity and dielectric properties measurements of H2SO4;HCl and(Conc.HCl+NaNO2mixture)doped PANI.In order to know the effect of acetone washing on the electrical properties of acid doped PANI samples,the electrical properties of the non-acetone washed acid doped PANI samples are compared with that of their acetone washed counterparts.The PANI salt was prepared by conventional route using aniline hydrochloride and ammonium persulphate as an oxidant.PANI salt was subjected to 0.5M NaOH to form PANI base,which was further doped separately with H2SO4;HCl and(Conc.HCl+NaNO2mixture)respectively followed by acetone washing.A comparative electrical conductivity study between the acetone washed and unwashed PANI salt and H2SO4,HCl and Conc.HCl+NaNO2 mixture doped PANI were characterized by dielectric and impedance study.
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.
文摘Aurivillius type compound BaBi_(4)Ti_(4)O_(15)(BBT)ceramic was prepared by solid state reaction route and its electrical properties were studied.X-ray diffraction(XRD)pattern showed orthorhombic structure with space group A21am confirming it to be an m=4 member of the Aurivillius oxide.The scanning electron microscope of the sintered pellet showed a plate-like morphology of grains which is a characteristic feature of the Aurivillius compounds.The temperature and frequency dependence dielectric study showed a shifting of transition temperature with frequency indicating relaxor type behavior in the material.The diffuseness parameter(γ)established the relaxor nature and it was attributed to the A-site cationic disorder.The dielectric relaxation obeyed the VogelFulcher(VF)relation and various parameters like activation energy for relaxation,freezing temperature,relaxation frequency were determined after nonlinear curve fitting.The temperature dependence of dielectric constant at temperatures much higher and lower than Tm was analyzed by two exponential functions,which gives an idea about the production of polar clusters at high temperature and the distribution of freezing temperatures at lower temperature.Various other associated parameters were calculated by nonlinear curve fitting and their significance has been explained.
