Polycrystalline sample of lead-free 1/3(Ba_(0.70)Sr_(0.30)TiO_(3))+1/3(Ba_(0.70)Ca_(0.30)TiO_(3))+1/3(BaZr_(0.20)Ti_(0.80)O_(3))(BST-BCT-BZT)ceramic was synthesized by solid state reaction method.Phase purity and crys...Polycrystalline sample of lead-free 1/3(Ba_(0.70)Sr_(0.30)TiO_(3))+1/3(Ba_(0.70)Ca_(0.30)TiO_(3))+1/3(BaZr_(0.20)Ti_(0.80)O_(3))(BST-BCT-BZT)ceramic was synthesized by solid state reaction method.Phase purity and crystal structure of as-synthesized materials was confirmed by X-ray diffraction(XRD).Temperature-dependent dielectric permittivity studies demonstrated frequency independent behavior,indicating that the studied sample has typical diffuse phase transition behavior with partial thermal hysteresis.A ferroelectric phase transition between cubic and tetragonal phase was noticed near room temperature(~330 K).Bulk P-E hysteresis loop showed a saturation polarization of 20.4μC/cm^(2) and a coercive field of~12.78 kV/cm at a maximum electric field of~115 kV/cm.High dielectric constant(ε~5773),low dielectric loss(tanδ~0.03)were recorded at room temperature.Discharge energy density of 0.44 J/cm^(3) and charge energy density of 1.40 J/cm^(3) were calculated from nonlinear ferroeletric hysteresis loop at maximum electric field.Dielectric constant at variable temperatures and electric fields,ferroeletric to paraelectric phase transition and energy storage properties were thoroughly discussed.展开更多
基金supported by the National Science Foundation under grant NSF-EFRI RESTOR#1038272.
文摘Polycrystalline sample of lead-free 1/3(Ba_(0.70)Sr_(0.30)TiO_(3))+1/3(Ba_(0.70)Ca_(0.30)TiO_(3))+1/3(BaZr_(0.20)Ti_(0.80)O_(3))(BST-BCT-BZT)ceramic was synthesized by solid state reaction method.Phase purity and crystal structure of as-synthesized materials was confirmed by X-ray diffraction(XRD).Temperature-dependent dielectric permittivity studies demonstrated frequency independent behavior,indicating that the studied sample has typical diffuse phase transition behavior with partial thermal hysteresis.A ferroelectric phase transition between cubic and tetragonal phase was noticed near room temperature(~330 K).Bulk P-E hysteresis loop showed a saturation polarization of 20.4μC/cm^(2) and a coercive field of~12.78 kV/cm at a maximum electric field of~115 kV/cm.High dielectric constant(ε~5773),low dielectric loss(tanδ~0.03)were recorded at room temperature.Discharge energy density of 0.44 J/cm^(3) and charge energy density of 1.40 J/cm^(3) were calculated from nonlinear ferroeletric hysteresis loop at maximum electric field.Dielectric constant at variable temperatures and electric fields,ferroeletric to paraelectric phase transition and energy storage properties were thoroughly discussed.
