Dielectric Properties and Defect Chemistry of WO3-Doped K0.5Na0.5NbO3 Ceramics

Wu, Shuangshuang; Wang, Zhu; Liu, Laijun; Shi, Danping; Zheng, Shaoying; Huang, Yanming; Fang, Liang

doi:10.1007/s11664-013-2975-3

Cited by 35 publications

(13 citation statements)

References 29 publications

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“…The electrical resistivity becomes reduced as the temperature increases, as evidenced by the conversion of a pitch arc to a semicircle. The reduced electrical resistivity is ascribed to the thermal activated charge carriers . To determine the carrier species, the activation energy ( E a ) of thermally activated carriers are calculated from the plot of ln f max −1000/ T (the inset of Figure ) for Z ″( f ), by fitting the Arrhenius law:

f_{normalmax} = f_{0} exp (][- \frac{E_{a}}{k_{normalB} T})

…”

Section: Resultsmentioning

confidence: 99%

Lead‐free Ag_1−3xLa_xNbO₃ antiferroelectric ceramics with high‐energy storage density and efficiency

et al. 2019

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Environmentally benign lead-free bulk ceramics with high recoverable energy density (W rec ) are very attractive in advanced pulsed power capacitors. In this work, composition engineering was adopted by La 3+ modification to improve the energy storage performance of Ag 1−3x La x NbO 3 ceramics. It was found that the antiferroelectric (AFE) phase was stabilized after La 3+ substitution, as a result of the reduced tolerance factor t. Significant improvement of W rec and energy storage efficiency (η) were achieved with value of 3.12 J/cm 3 and 0.63 for x = 0.02 at an electric field of 230 kV/cm, more than 1.5 times the value of pure AgNbO 3 (W rec = 1.9 J/cm 3 , η = 0.40). The excellent energy storage properties are resulted from the increased antiferroelectric-ferroelectric phase transition electric field (E F ), ferroelectric-antiferroelectric phase transition electric field (E A ), and breakdown electric field (E b ). The enhanced E b was ascribed to the decreased grain size and increased electrical resistivity upon La 3+ modification. The feature makes Ag 1−3x-La x NbO 3 a potential candidate for energy storage applications. K E Y W O R D Sdielectric materials/properties, energy storage, ferroelectricity/ferroelectric materials, lead-free ceramics

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f_{normalmax} = f_{0} exp (][- \frac{E_{a}}{k_{normalB} T})

…”

Section: Resultsmentioning

confidence: 99%

Lead‐free Ag_1−3xLa_xNbO₃ antiferroelectric ceramics with high‐energy storage density and efficiency

et al. 2019

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“…Two distinctive dielectric anomalies are discerned for the samples x = 0.005 and x = 001, which is similar to pure KNN [15]. The first dielectric anomaly at 200°C is known as the phase transition from orthorhombic (ferroelectric) to tetragonal (ferroelectric) [16]. The other dielectric anomaly results from the phase transition from tetragonal (ferroelectric) to cubic (paraelectric).…”

Section: Methodsmentioning

confidence: 78%

Low dielectric loss and good thermal stability of Eu and Ti co-doped K0.5Na0.5NbO3 ceramics

Fei

Shi

Huang

et al. 2015

J Mater Sci: Mater Electron

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In order to develop dielectric ceramics with temperature-stable permittivity characteristics, Eu and Ti codoped K 0.5 Na 0.5 NbO 3 [(1 -x)K 0.5 Na 0.5 NbO 3 -xEuTiO 3 ] ceramics were prepared by a conventional solid state route. The effect of EuTiO 3 on the phase structure and dielectric performance of KNN ceramics were investigated. The temperature dependence of the relative permittivity illustrated that the small amount of EuTiO 3 depressed the dielectric peak of ferroelectric-paraelectric transition. Therefore, the temperature stability and relative permittivity of ceramics were effectively improved. As x = 0.03, the ceramic showed superior dielectric temperature stability (±10 %), very low dielectric loss (0.008 at 250°C) and a relatively high permittivity ([1500 at 250°C) over the temperature range from *100 to 350°C. It suggests that this ceramic is a promising candidate for high-temperature capacitor application.

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“…The differences in grain size or grain/ceramic morphology usually have an influence on the dielectric and electric properties, e.g., such a behaviour has been observed for the KNN ceramics [26]. The temperature dependences of dielectric permittivity ε(T) and dielectric losses tan δ(T) are shown in Figure 6.…”

Section: Resultsmentioning

confidence: 91%

Preparation and Dielectric Properties of K1/2Na1/2NbO3 Ceramics Obtained from Mechanically Activated Powders

et al. 2020

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Alkaline based materials have been considered as a replacement for environmentally harmful Pb(Zr,Ti)O3 (PZT) electro-ceramics. In this paper, the K1/2Na1/2NbO3 (KNN) ceramics were prepared in a three stage process: first Nb2O5, Na2CO3, and K2CO3 were milled in a high energy mill (shaker type) for different periods, between 25 h and 100 h, consecutively a solid state reaction was carried out at 550 °C. Finally, the uniaxially pressed samples were sintered at 1000 °C. The reaction temperature is lower for mechanically activated powders than in the case of the conventional solid-state method. The ceramic samples, prepared from the mechanically activated powders, were investigated by dielectric spectroscopy. The influence of the duration of the mechanical activation on the properties of the ceramic materials, e.g., ceramic microstructures, phase transition temperatures, character of the temperature dependences of dielectric permittivity, are discussed.

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Dielectric Properties and Defect Chemistry of WO3-Doped K0.5Na0.5NbO3 Ceramics

Cited by 35 publications

References 29 publications

Lead‐free Ag_1−3xLa_xNbO₃ antiferroelectric ceramics with high‐energy storage density and efficiency

Lead‐free Ag_1−3xLa_xNbO₃ antiferroelectric ceramics with high‐energy storage density and efficiency

Low dielectric loss and good thermal stability of Eu and Ti co-doped K0.5Na0.5NbO3 ceramics

Preparation and Dielectric Properties of K1/2Na1/2NbO3 Ceramics Obtained from Mechanically Activated Powders

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Dielectric Properties and Defect Chemistry of WO3-Doped K0.5Na0.5NbO3 Ceramics

Cited by 35 publications

References 29 publications

Lead‐free Ag1−3xLaxNbO3 antiferroelectric ceramics with high‐energy storage density and efficiency

Lead‐free Ag1−3xLaxNbO3 antiferroelectric ceramics with high‐energy storage density and efficiency

Low dielectric loss and good thermal stability of Eu and Ti co-doped K0.5Na0.5NbO3 ceramics

Preparation and Dielectric Properties of K1/2Na1/2NbO3 Ceramics Obtained from Mechanically Activated Powders

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Lead‐free Ag_1−3xLa_xNbO₃ antiferroelectric ceramics with high‐energy storage density and efficiency

Lead‐free Ag_1−3xLa_xNbO₃ antiferroelectric ceramics with high‐energy storage density and efficiency