Search

[(Bi1/2Na1/2)0.92Ba0.05La0.02](Mg1/3Nb2/3)xTi(1-0.5x)O3(BNT-BLMNT, x = 0.01, 0.03,0.05,0.07) lead-free anti-ferroelectric ceramics were synthesized by a conventional solid-state. The effects of B-doped Mg4Nb2O9 groups on phase structures, compositional distribution and electrical properties of BNT-BLMNT ceramics were systematically investigated to further understand the mechanism of phase transition.It was found that the grain size of ceramic materials tends to decrease and the distribution becomes more uniform, indicating that Mg4Nb2O9 is conducive to the synthesis of ceramic materials in this system and effectively improves the grain size and distribution of this material with the increase of B-doped Mg4Nb2O9 group content. According to SEM and XRD analysis, Mg4Nb2O9 was completely dissolved in the ceramic crystal, forming a solid solution, all of which were of a single perovskite crystal structure.With the increase of it's content, the remnant polarization (Pr) decreased significantly, from 38.9 µC/cm2(x = 0.01) to 10.4 µC/cm2(x = 0.05), and the difference between the maximum polarization(Pmax) and the remnant polarization(Pr) became larger and larger, indicating that the addition of Mg and Nb elements increased the transition trend of the anti-ferroelectric phase. [ABSTRACT FROM AUTHOR]

(1−x)Bi1/2Na1/2TiO3–xBa1/2Sr1/2TiO3–0.05KNaNbO3 (BNT–BST–KN, x = 0.01, 0.03, 0.05, 0.07) lead-free anti-ferroelectric ceramics were synthesized by a conventional solid-state. The hysteresis loop of the ceramic at different temperature under 70 kV/cm electric field was analyzed. In this paper, the energy storage properties of BNT–BST–KNN ceramics are studied. It was found that the addition of Sr element helps to improve the electric field strength tolerance and the breakdown resistance performance the material, so as to improve its energy storage density. At room temperature, the P–E curves of the materials in the system basically show a double hysteresis loop, and with the increase of temperature, the characteristics of the double hysteresis curve are particularly obvious. The ceramics exist in the ferroelectric–antiferroelectric coexistence phase region near 303 K, namely the morphotropic phase boundary region. It shows that the ceramic has anti-ferroelectric characteristics at room temperature, and is a typical anti-ferroelectric material. [ABSTRACT FROM AUTHOR]

(1-x)Bi1/2Na1/2TiO3-xBa1/2Sr1/2TiO3-0.05KNaNbO3(BNT-BST-KNN, x = 0.01, 0.03,0.05,0.07) lead-free anti-ferroelectric ceramics were synthesized by a conventional solid-state. The effects of co-doping of Sr element and KNN group on phase structures, compositional distribution and electrical properties of BNT-BST-KNN ceramics were systematically investigated to further understand the mechanism of phase transition. It was found that the grain size decreased obviously, indicating that the addition of Sr element inhibited the grain growth. According to SEM and XRD analysis, the components of the samples obtained were all perovskite phase structure, and the coke free green stone was equal to other heterophases, indicating that K1+, Na1+, Nb4+ and Sr2+ ions successfully diffused into the crystal lattice of BiNaTiO3-BaTiO3 and formed a uniform solid solution. It shows that the doping of Sr element and KNN effectively promotes the transformation of trigonal phase to tetragonal phase. From the analysis results, the doping of Sr element and KNN effectively reduces the dielectric loss of the materials, and the dielectric property stability is greatly improved. [ABSTRACT FROM AUTHOR]

[(Bi1/2Na1/2)0.94Ba0.06]0.97La0.02TiO3 (BNT-BLT) lead-free anti-ferroelectric ceramics were synthesized by a conventional solid-state.By analyzing TGA and DSC curves, the material should be calcined at about 800 °C. The effects of different milling time on the microstructure of the materials were also studied. Microstructures analysis and the calculation from the X-ray diffraction results reveal that the milling time of BNT-BLT ceramic should be controlled within a reasonable range, around 15 h. [ABSTRACT FROM AUTHOR]

(Bi0.46Na0.46Ba0.05La0.02)ZrxTi(1-x)O3(BNBLZT,x= 0.01, 0.03, 0.05, 0.07) lead-free anti-ferroelectric ceramics were synthesized by conventional solid-state reaction method. Microstructures and electrical properties of BNBLZT were investigated. Calculation from the X-ray diffraction results reveals that BNBLZT ceramic possesses a single perovskite structure phase. All BNBLZT ceramics show high density and the grain sizes decrease slightly with the addition of Zr concentration. In addition, theP-Ehysteresis loops measured at room temperature show that the largest energy-storage densityWmaxis 1.89 J/cm3. The temperature dependence of dielectric permittivity ϵrand dielectric loss tanδ illustrate that the addition of Zr can improve the piezoelectric properties of BNBLZT ceramics. [ABSTRACT FROM PUBLISHER]

Abstract: Energy-storage properties of [(Bi1/2Na1/2)0.94Ba0.06]La(1−x)Zr x TiO3 (BNT-BLZT, x=0, 0.02, 0.04, and 0.06) lead-free anti-ferroelectric ceramics fabricated via the conventional sintering technique were first investigated. Calculation from the X-ray diffraction results reveals that BNT-BLZT ceramic possesses a single perovskite structure phase. In addition, the P–E hysteresis loops measured at room temperature show that the BNT-BLZT (x=0.02) ceramics obtain the maximum P value of 37.5μC/cm2 and the largest energy-storage density W max is 1.58J/cm3. The temperature dependence of dielectric permittivity ε r and dielectric loss tanδ illustrate that the addition of Zr can improve the piezoelectric properties of BT-BLZT ceramics. These properties indicate that BNT-BLZT ceramics might be a promising lead-free anti-ferroelectric material for energy storage application. [Copyright &y& Elsevier]