The dielectric spectra of CaCu₃Ti₄O₁₂ is characterized by a large permittivity (εᵣ>10 000) with only a weak dependence on temperature over the temperature range 200–400 K. In this work, doping with 0.1–1.0 wt % ZrO₂ has been shown to dramatically reduce the dielectric loss. At 0.5 wt % ZrO₂, tan...
The crystal structure and multiferroic properties of single-phase (Bi₀.₉La₀.₁)FeO₃–Ba(Fe₀.₅Nb₀.₅)O₃ ceramics were investigated. The rhombohedral-type structure of 1.0(Bi₀.₉La₀.₁)FeO₃) was transformed to a monoclinic-type structure for the 0.5(Bi₀.₉La₀.₁)FeO₃–0.5Ba(Fe₀.₅Nb₀.₅)O₃) composition. It shows the coexistence of ferroelectricity and magnetism at room temperature, represented by a high dielectric constant with ferroelectric hysteresis and clear magnetic...
A new composite system, Ba(Zr[subscript 0.07]Ti[subscript 0.93])O₃ (BZT93) ceramic/NiO nanoparticles, was fabricated to investigate the effect of NiO nanoparticles on the properties of these composites. M-H hysteresis loops showed an improvement in the magnetic behavior for higher NiO content samples plus modified ferroelectric properties. However, the 1 vol. % samples...
Solid solutions ceramics of the Bi(Zn0.5Ti0.5)O-3-(Bi0.5K0.5)TiO3-(Bi0.5Na0.5)TiO3 ternary system for <20 mol. % BZT were created and confirmed to be single phase using x-ray diffraction. The dielectric dispersion showed decreasing T-max of the dielectric spectrum with a broadening of the transition with increasing BZT content. At 2.5BZT-40BKT-57.5BNT, a secondary transition commonly...
The piezoelectric fatigue behavior of Pb-free ceramics based on solid solutions of Bi(Zn₀.₅Ti₀.₅)O₃-(Bi₀.5K₀.₅)TiO₃-(Bi₀.₅Na₀.₅)TiO₃ was characterized at 50 kV/cm after 10⁶ bipolar cycles. Ferroelectric compositions containing 2.5% Bi(Zn₀.₅Ti₀.₅)O₃ exhibited only minor losses in maximum strain (~10%). In compositions with 5% Bi(Zn₀.₅Ti₀.₅)O₃ that exhibit large electric field-induced strains, the electromechanical strain actually...
The defect mechanisms that underpin the high energy density dielectric 0.8BaTiO₃–0.2Bi(Zn₁/₂Ti₁/₂) O₃ were investigated. Characterization of the nominally stoichiometric composition revealed the presence of a Ti³⁺-related defect center, which is correlated with lower resistivities and an electrically heterogeneous microstructure. In compositions with 2 mol. % Ba-deficiency, a barium vacancy-oxygen vacancy...
In order to develop dielectric ceramics with temperature-stable permittivity characteristics, perovskite BaTiO[subscript 3]-Bi(Zn[subscript 1/2]Ti[subscript 1/2])O-[subscript 3]-NaNbO[subscript 3] ceramic solid solutions were investigated with a particular focus on effects of BaTiO[subscript 3] and NaNbO[subscript 3] contents on the dielectric properties of ternary compounds. Keeping the ratios of the other two constituents...
Lead-free ceramics of composition Bi(Mg₁/₂Ti₁/₂)O₃-(Bi₁/₂K₁/₂)TiO₃-(Bi₁/₂Na₁/₂)TiO₃ were prepared
using solid state synthesis techniques. The dielectric spectra showed a Tmax of more than 320 °C
for all compositions, and the transitions became increasingly diffuse as the Bi(Mg₁/₂Ti₁/₂)O₃
content increased. A lower temperature transition, indicating a transformation from an ergodic to a
non-ergodic...
Polycrystalline ferroelectric lead-free 85 mol% (Bi₀.₅Na₀.₅)TiO₃–10 mol% (Bi₀.₅K₀.₅)TiO₃–5 mol% BaTiO₃ (85BNT–10BKT–5BT) thin films were fabricated via chemical solution deposition on platinized silicon substrates. The permittivity and dielectric loss at 1 kHz were 610 and ∼3.5%, respectively. The ferroelectric properties at room temperature and as a function of the temperature up...