Oxygen-vacancy-related low-frequency dielectric relaxation and electrical conduction in B i : S r T i O 3
TL;DR: In this article, three sets of oxygen vacancies related dielectric peaks (peaks A, B, and C) were measured from 10 to 800 K. The results show that the Maxwell-Wagner polarization is not the main mechanism, and the Skanavi's model also cannot be directly applied.
Abstract: The temperature dependence of dielectric properties and electrical conduction of $({\mathrm{Sr}}_{1\ensuremath{-}1.5x}{\mathrm{Bi}}_{x}){\mathrm{TiO}}_{3} (0.0133l~xl~0.133)$ was measured from 10 to 800 K. Three sets of oxygen vacancies related dielectric peaks (peaks A, B, and $C)$ were observed. These peaks could be greatly suppressed or eliminated by annealing the samples in an oxidizing atmosphere, and enhanced or recreated by annealing in a reducing atmosphere. The results show that the Maxwell-Wagner polarization is not the main mechanism, and the Skanavi's model also cannot be directly applied. A tentative explanation was suggested. Peak A, observed in the temperature range of 100--350 K with the activation energy for dielectric relaxation ${E}_{\mathrm{relaxA}}=0.32--0.49$ eV, is attributed to the coupling effect of the conduction electrons with the motion of the off-centered Bi and Ti ions; the conduction carriers in this temperature range are from the first ionization of oxygen vacancies ${(V}_{o}).$ Peaks B and C are also discussed.
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Letao Yang1, Xi Kong1, Fei Li2, Hua Hao3, Zhenxiang Cheng1, Hanxing Liu3, Jing-Feng Li4, Shujun Zhang1 •
TL;DR: In this paper, the authors summarize the principles of dielectric energy-storage applications, and recent developments on different types of Dielectrics, namely linear dielectrics (LDE), paraelectric, ferroelectrics, and antiferro electrics, focusing on perovskite lead-free dielectors.
941 citations
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TL;DR: In this article, the polarization and strain behavior of Ba(Ti1−xZrx)O3 (x=0-03) ceramics are studied and the unipolar strain levels of ∼018% at 40 kV/cm and of ∼025% at ∼120 kv/cm with small hysteresis were obtained for the poramics with 003−xx⩽008.
Abstract: The polarization and strain behavior of Ba(Ti1−xZrx)O3 (x=0–03) ceramics are studied The unipolar strain levels of ∼018% at 40 kV/cm and of ∼025% at ∼120 kV/cm with small hysteresis were obtained for the ceramics with 003⩽x⩽008 The remnant polarization is ∼13–18 μC/cm2 for 003⩽x⩽008 and below 2 μC/cm2 for 015⩽x⩽03 at room temperature The electromechanical coupling coefficient K33=565% and the piezoelectric stain coefficient d33=236 pC/N were obtained for the ceramics with x=005 These results indicated that the Ba(Ti1−xZrx)O3 system is a promising lead-free high strain material for applications
397 citations
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TL;DR: In this paper, temperature dependencies of the dielectric permittivity were measured at different frequencies and the experimental data obtained show very high values of the Dielectric Permittivity in a wide temperature interval that is inherent to high-k materials.
Abstract: AFe$_{1 / 2}$B$_{1 / 2}$O$_{3}$(A- Ba, Sr, Ca; B-Nb, Ta, Sb) ceramics were synthesized and temperature dependencies of the dielectric permittivity were measured at different frequencies. The experimental data obtained show very high values of the dielectric permittivity in a wide temperature interval that is inherent to so-called high-k materials. The analyses of these data establish a Maxwell-Wagner mechanism as a main source for the phenomenon observed.
366 citations
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TL;DR: In this article, the authors show very high values of dielectric permittivity in a wide temperature interval that is inherent to so-called high-k materials and establish a Maxwell-Wagner mechanism as the main source for the phenomenon observed.
Abstract: AFe1/2B1/2O3(A=Ba, Sr, Ca; B=Nb, Ta, Sb) ceramics were synthesized and temperature dependences of dielectric permittivity were measured at different frequencies The experimental data obtained show very high values of dielectric permittivity in a wide temperature interval that is inherent to so-called high-k materials Analyses of these data establish a Maxwell–Wagner mechanism as a main source for the phenomenon observed
365 citations
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TL;DR: In this paper, the electrical and magnetic properties of polycrystalline samples of Bi0.90La0.10(Fe1−xMnx)O3 (x=0, 0, 0.05,0.15, and 0.20) were prepared using a novel mechanical activation followed by a conventional solid-state reaction technique.
Abstract: Polycrystalline samples of Bi0.90La0.10(Fe1−xMnx)O3 (x=0, 0.05, 0.10, 0.15, and 0.20) were prepared using a novel mechanical activation followed by a conventional solid-state reaction technique. The formation of the desired materials was confirmed using x-ray diffraction. The electrical and magnetic properties of the materials were investigated at different Mn concentrations as a function of temperature. Both dielectric constant and loss tangent increased with the increase in Mn content in the system. The grain and grain boundary contributions have been estimated using impedance spectroscopy analysis. Both grain and grain boundary conductivity increased with a rise in temperature for all Mn concentrations. The value of activation energy for both grain and grain boundary is nearly the same, and decreased with an increase in Mn concentration. There is a systematic increase in the value of magnetization on increasing Mn concentration.
266 citations