Ceramic samples of Barium Zirconium Titanate(BaZr_(x)Ti_(1-x)O_(3)(BZT))were synthesized by conventional solid-state reaction method with different concentrations of x(=0.05(BZT1),0.10(BZT2),0.15(BZT3),0.20(BZT4),0.25...Ceramic samples of Barium Zirconium Titanate(BaZr_(x)Ti_(1-x)O_(3)(BZT))were synthesized by conventional solid-state reaction method with different concentrations of x(=0.05(BZT1),0.10(BZT2),0.15(BZT3),0.20(BZT4),0.25(BZT5),0.30(BZT6)).Phase confirmation of the samples was done by X-ray diffraction(XRD)technique.All the compositions are in cubic structure.XRD pattern was recorded for samples sintered at different sintering temperatures.Lattice parameters increased with addition of Zr^(+4).Doping with Zr^(+4)into Barium titanate resulted in interesting changes of electrical properties(dielectric,impedance and ferroelectiricity).The strong influence of Zr doping on the phase transition characteristics of the BZT ceramics was studied from the dielectric response of the samples.Diffusivity of phase transition of the BZT ceramic samples increase with Zr^(+4)concentration,indicating changes from normal to diffuse transition to relaxor phase transition behavior.Impedance spectroscopy reveals the presence of temperature-dependent grain,grain boundary effects.Polarization-Electricfield(PE)loop measurements are also done on the samples.展开更多
We report the glassy behavior of dysprosium doped barium zirconium titanate single phase perovskite ceramics with general formula Ba_(1-x)Dy_(2x/3)Zr_(0.25)Ti_(0.75)O_(3)prepared by solid-state reaction method.Tempera...We report the glassy behavior of dysprosium doped barium zirconium titanate single phase perovskite ceramics with general formula Ba_(1-x)Dy_(2x/3)Zr_(0.25)Ti_(0.75)O_(3)prepared by solid-state reaction method.Temperature and frequency dependent dielectric studies of the ceramics reveal relaxor behavior.A non-Debye relaxation,which is analogous to the magnetic relaxation in spin-glass system,is observed clearly around temperature of dielectric permittivity maximum(Tm).Frequency dependence of Tm governed by production of polar nano-regions is analyzed using Debye relation,Vogel-Fulcher(V-F)relation and power law.A clear change in dynamic behavior is observed by power parameter which is related to growth of interactions between polar nano-regions with different composition.Various parameters like activation energy for relaxation,freezing temperature,relaxation frequency,etc.,are determined after non-linear curve fitting.Temperature dependence of dielectric constant at temperatures much higher and lower than Tm is analyzed by two exponential functions,which gives an idea about the production of polar clusters at high temperature and distribution of freezing temperatures at lower temperature.Various other associated parameters are calculated by non-linear curve fitting and their significance has been explained.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
Perovskite solid solution ceramics of PZN–PT–BT with several compositions were synthesized by solid-state reaction method.X-ray diffraction results indicate pure perovskite structures for all samples.Dielectric meas...Perovskite solid solution ceramics of PZN–PT–BT with several compositions were synthesized by solid-state reaction method.X-ray diffraction results indicate pure perovskite structures for all samples.Dielectric measurements show that the implicit Ba(Zn_(1/3)Nb_(2/3))O_(3)(BZN)composition could broaden the diffusion phase transition(DPT)peaks and lower the ε_(max) and T_(max) values.The observed dielectric properties may be caused by the increased cation disorder due to the substitution of barium onto the A-site and titanium onto the B-site.展开更多
基金the University Grants CommissionNew Delhi,India for providing the financial assistance under the sponsored project.
文摘Ceramic samples of Barium Zirconium Titanate(BaZr_(x)Ti_(1-x)O_(3)(BZT))were synthesized by conventional solid-state reaction method with different concentrations of x(=0.05(BZT1),0.10(BZT2),0.15(BZT3),0.20(BZT4),0.25(BZT5),0.30(BZT6)).Phase confirmation of the samples was done by X-ray diffraction(XRD)technique.All the compositions are in cubic structure.XRD pattern was recorded for samples sintered at different sintering temperatures.Lattice parameters increased with addition of Zr^(+4).Doping with Zr^(+4)into Barium titanate resulted in interesting changes of electrical properties(dielectric,impedance and ferroelectiricity).The strong influence of Zr doping on the phase transition characteristics of the BZT ceramics was studied from the dielectric response of the samples.Diffusivity of phase transition of the BZT ceramic samples increase with Zr^(+4)concentration,indicating changes from normal to diffuse transition to relaxor phase transition behavior.Impedance spectroscopy reveals the presence of temperature-dependent grain,grain boundary effects.Polarization-Electricfield(PE)loop measurements are also done on the samples.
文摘We report the glassy behavior of dysprosium doped barium zirconium titanate single phase perovskite ceramics with general formula Ba_(1-x)Dy_(2x/3)Zr_(0.25)Ti_(0.75)O_(3)prepared by solid-state reaction method.Temperature and frequency dependent dielectric studies of the ceramics reveal relaxor behavior.A non-Debye relaxation,which is analogous to the magnetic relaxation in spin-glass system,is observed clearly around temperature of dielectric permittivity maximum(Tm).Frequency dependence of Tm governed by production of polar nano-regions is analyzed using Debye relation,Vogel-Fulcher(V-F)relation and power law.A clear change in dynamic behavior is observed by power parameter which is related to growth of interactions between polar nano-regions with different composition.Various parameters like activation energy for relaxation,freezing temperature,relaxation frequency,etc.,are determined after non-linear curve fitting.Temperature dependence of dielectric constant at temperatures much higher and lower than Tm is analyzed by two exponential functions,which gives an idea about the production of polar clusters at high temperature and distribution of freezing temperatures at lower temperature.Various other associated parameters are calculated by non-linear curve fitting and their significance has been explained.
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.
基金Natural Science Basis Research Plan in Shaanxi Province of China (Grant No.2015JM5199)Fundamental Research Funds for the Central Universities, the National Basic Research Program of China (973 Program) (Grant No. 2015CB654602)International Science and Technology Cooperation Program of China (Grant Nos. 2013DFR50470 and 2015DFA51100),the 111 Project under Grant No. B14040.
文摘Perovskite solid solution ceramics of PZN–PT–BT with several compositions were synthesized by solid-state reaction method.X-ray diffraction results indicate pure perovskite structures for all samples.Dielectric measurements show that the implicit Ba(Zn_(1/3)Nb_(2/3))O_(3)(BZN)composition could broaden the diffusion phase transition(DPT)peaks and lower the ε_(max) and T_(max) values.The observed dielectric properties may be caused by the increased cation disorder due to the substitution of barium onto the A-site and titanium onto the B-site.
