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Showing papers on "Ferroelectric ceramics published in 2003"


Journal ArticleDOI
TL;DR: In this article, the fabrication of ferroelectric oxide nanoshell tubes as well as ordered nanotube arrays have been accomplished using a simple and convenient fabrication method that allows full tailoring of tube dimensions and array pattern and size.
Abstract: Wafer-scale fabrication of ferroelectric oxide nanoshell tubes as well as ordered nanotube arrays have been accomplished using a simple and convenient fabrication method that allows full tailoring of tube dimensions as well as array pattern and size. Using different silicon and alumina templates, barium titanate and lead zirconate titanate tubes with diameters ranging from 50 nm up to several micrometers meter and lengths of more 100 μm have been fabricated. Ferroelectric switching of submicrometer tubes has been shown using piezoresponse scanning probe microscopy.

283 citations


Journal ArticleDOI
TL;DR: In this article, the authors modified the Debye relaxation equation by introducing the mobile dipole of the thermal motion of oxygen vacancies in order to explain the temperature-dependent behavior of the diffuse dielectric anomaly.
Abstract: The diffuse dielectric anomaly by the dielectric relaxation found at the high-temperature region of 400–700 °C was investigated in perovskite-type ferroelectric oxides such as BaTiO3, (Pb,La)TiO3, and (Pb,La)(Zr,Ti)O3 ceramics. We observed that the diffuse dielectric anomaly in perovskite oxides was strongly affected by oxygen-related processing parameters. We have modified the Debye relaxation equation by introducing the mobile dipole of the thermal motion of oxygen vacancies in order to explain the temperature-dependent behavior of the diffuse dielectric anomaly. A relationship between the dielectric polarization/relaxation and the electrical conduction by the thermal motion of oxygen vacancies was microscopically suggested to explain the origin of the diffuse dielectric anomaly found at 400–700 °C in perovskite-type ferroelectric oxides.

243 citations


Journal ArticleDOI
TL;DR: In this article, the temperature dependence of dielectric permittivity was investigated for two ferroelectric ceramic compositions in a barium stannate titanate solid solution system.
Abstract: The temperature dependence of dielectric permittivity was investigated for two ferroelectric ceramic compositions in a barium stannate titanate solid solution system. The dielectric relaxation behavior was observed in these ferroelectrics with diffused phase transition. In view of the polar nanoregion, the relationship between relaxor ferroelectric and ferroelectrics with a diffused phase transition was explored. The results suggest that, in barium stannate titanate, the relaxor ferroelectric dielectric behavior is universal in the diffused phase transition region, but it only appears when the experimental frequency is close to the relaxation frequency of polar nanoregion at that temperature.

159 citations


Journal ArticleDOI
TL;DR: In this paper, the relationship between the microwave dielectric properties and the IR active phonons of xBa(Mg1/3Ta2/3)O3-(1−x)Ba(mg 1/3Nb2/)O3 ceramics was investigated.
Abstract: The relationship between the microwave dielectric properties and the IR active phonons of xBa(Mg1/3Ta2/3)O3–(1−x)Ba(Mg1/3Nb2/3)O3 ceramics was investigated. The IR modes were assigned, and the origin of dielectric response was determined. Among the 15 prominent IR modes, we found that the normal vibrations of the O layers and that of the Ta/Nb layers are strongly correlated to the measured dispersion parameters, such as the resonant strength (4πρ) and the damping coefficient (γ). The frequency shifts of the normal modes of the O layers and that of the Ta/Nb layers explain the linear decrease of microwave dielectric constant (K) as x increases, while the width of these modes correlate with the Q×f value.

134 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigated the electromechanical response of piezoelectric ceramics as a function of the amplitude and frequency of large electric fields and studied the effects of dc bias fields.
Abstract: We have investigated the electromechanical response of piezoelectric ceramics as a function of the amplitude and frequency of large electric fields and studied the effects of dc bias fields In order to characterize the materials under these conditions, a ZMI 2000 laser interferometer system from Zygo Corp has been installed and modified to directly measure the strains of ferroelectric ceramics This system uses a heterodyne detection technique and has the advantages of phase detection, wide bandwidth, high stability, and easy optical alignment Our experiment has been used to determine the strain of lead zirconate titanate (PZT) ceramics as a function of electric fields and as a function of frequency in the low frequency range From these measurements the piezoelectric coefficients d33, d31, and d15 have been determined as a function of applied field and frequency In addition the dependence of the piezoelectric coefficients under an applied dc bias field has been studied under quasistatic and under res

130 citations


Journal ArticleDOI
TL;DR: In this article, Fatigue-free and highly c-axis oriented Bi4−xPrxTi3O12´(BPrT, x=0.85) thin films were grown on Pt/TiO2´/SiO2''/SiÞ substrates using the method of metalorganic sol decomposition.
Abstract: Fatigue-free and highly c-axis oriented Bi4−xPrxTi3O12 (BPrT, x=0.85) thin films were grown on Pt/TiO2/SiO2/Si (100) substrates using the method of metalorganic sol decomposition. The BPrT film capacitor with a top Pt electrode showed significantly improved values of the remanent polarization (Pr) and the nonvolatile charge as compared to those of the Bi4−xLaxTi3O12 (x=0.75) film capacitor, recently known as a promising candidate for nonvolatile memories. The 2Pr value of the BPrT capacitor was 40 μC/cm2 at an applied voltage of 10 V while the net nonvolatile charge was as high as 20 μC/cm2 and remained essentially constant up to 4.5×1010 read/write switching cycles at a frequency of 1 MHz. In addition to these, the capacitor showed excellent charge-retention characteristics with its sensing margin of 16 μC/cm2 and a strong resistance against the imprinting failure.

111 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of anisotropic dielectric properties of ferroelectric Ba1−xSrxTiO3 (BST) films on the characteristics of the interdigital (IDT) capacitors have been studied in microwave regions at room temperature.
Abstract: The effects of anisotropic dielectric properties of ferroelectric Ba1−xSrxTiO3 (BST) films on the characteristics of the interdigital (IDT) capacitors have been studied in microwave regions at room temperature. Ferroelectric BST films with (001), (011), and (111) orientation were epitaxially grown on (001), (011), and (111) MgO substrates, respectively, by the pulsed laser deposition method. The microwave properties of orientation engineered BST films were investigated using interdigital capacitors. The calculated dielectric constant tunability with 40 V dc bias variation and the calculated dielectric quality factor values for IDT capacitors based on (001), (011), and (111) oriented BST films at 9 GHz with no dc bias were about 47%, 55%, 43%, and 12, 14, 21, respectively.

107 citations


Journal ArticleDOI
TL;DR: In this article, a scheme for tuning the photonic band gap (PBG) by an external electric field in a ferroelectric inverse opal structure was presented for the superprism effect in PCs.
Abstract: We present a scheme for tuning the photonic band gap (PBG) by an external electric field in a ferroelectric inverse opal structure. The inverse opals, consisting of ferroelectric (Pb,La)(Zr,Ti)O3 (PLZT) ceramics, were synthesized by a sol–gel process. Optical reflection spectra show that the PBG of the PLZT inverse opals shifts continuously with the change in the applied electric field. As the photonic crystals (PCs) consist of the high-refractive-index constituent and possess an “all-solid” structure, it should supply a more reliable mode to tune the PBG by the electric field for the superprism effect in PCs. It should be of high interest in device applications.

94 citations


Journal ArticleDOI
Zhuo Li, Chunlei Wang, Wei Zhong, Jiafang Li, M. L. Zhao1 
TL;DR: In this paper, the crystal structure of lead-free potassium-bismuth titanate, K 0.5Bi0.5TiO3 (KBT) was determined by x-ray diffraction, and the temperature dependence of dielectric constants were measured.
Abstract: Lead-free potassium–bismuth titanate, K0.5Bi0.5TiO3 (KBT), ferroelectric ceramics were fabricated from the natural sintering of powders prepared by the thermal decomposition of adequate precursor solutions. Their crystal structure was determined by x-ray diffraction, and the temperature dependence of dielectric constants were measured. The results show that KBT may be a kind of order–disorder relaxor ferroelectric with a first-order phase transition below the temperature of dielectric constant maximum.

93 citations


Journal ArticleDOI
TL;DR: In this paper, a three-phase composite with a conductive carbon-fiber (CF) and ferroelectric phase (BaTiO 3 ) embedded into polyvinylidene fluoride (PVDF) was prepared by using a simple blending and hot-molding technique.

93 citations


Journal ArticleDOI
TL;DR: In this paper, the size effect on the ferroelectric phase transition in SrBi2Ta2O9 nanoparticles was investigated by in situ Raman scattering and the results showed that the transition temperature decreases from its bulk value (605 K) as the size decreases.
Abstract: We report the size effect on the ferroelectric phase transition in SrBi2Ta2O9 nanoparticles. Samples with particle sizes between 11 and 71 nm were prepared by a room-temperature mechanical activation process followed by postannealing at different temperatures. The size of the particles was determined by x-ray diffraction with the aid of Scherrer’s equation. The ferroelectric phase transition in both SrBi2Ta2O9 nanoparticles and bulk sample were investigated by in situ Raman scattering. The results show that the transition temperature (Tc) decreases from its bulk value (605 K) as the size decreases. The size dependence of Tc can be described as Tc=605−1150/(D−2.1) (K), where D (nm) is the particle size. A critical size of 2.6 nm, below which ferroelectricity disappears, was obtained from this empirical expression.

Journal ArticleDOI
TL;DR: A modified catecholate process has been applied to synthesize high purity barium titanate powders in the submicron range as mentioned in this paper, where phase transformation and crystallite size of calcined powders were investigated as a function of the calcination temperature by X-ray diffraction methods and particle morphology and size were studied by scanning electron microscopy.
Abstract: A modified catecholate process has been applied to synthesize high purity barium titanate powders in the submicron range. A barium titanium-catechol complex, Ba[Ti(C6H4O2)3] was prepared from TiCl4, C6H4(OH)2 and BaCO3, freeze-dried, and calcined for 3 h at temperatures between 600 and 1300 °C. Phase transformation and crystallite size of the calcined powders were investigated as a function of the calcination temperature by X-ray diffraction methods, and particle morphology and size were studied by scanning electron microscopy. With increasing calcination temperature, BaTiO3 transformed from the (pseudo)cubic to the ferroelectric tetragonal phase. The tetragonality (c/a-1) increases with increasing calcination temperature and increasing crystallite size, respectively. Higher temperatures clearly favoured particle growth and the formation of large and hard agglomerates. The crystallite size of the tetragonal phase increased from

Journal ArticleDOI
TL;DR: In this paper, the locking of electric-field-induced non-180° domain switching and phase transition after experiencing cyclic electric field was investigated by examining the changes in pseudocubic diffraction profiles.
Abstract: In situ x-ray diffraction measurements are conducted on a polycrystalline ferroelectric material lead-zironate-titanate-5H at different levels of static electric field. The locking of electric-field-induced non-180° domain switching and phase transition after experiencing cyclic electric field is investigated by examining the changes in pseudocubic diffraction profiles. The results show that cyclic electric field with an amplitude lower than the coercive field has little effect on ferroelectric fatigue of the material, whereas cyclic field with an amplitude above the coercive field results in nearly complete locking of non-180° domain switching and phase transition. The results also demonstrate that the locking occurs rather suddenly after 103–104 cycles. This locking phenomenon can explain the dramatic change in piezoelectric coefficients in these materials upon cyclic electric field.

Journal ArticleDOI
TL;DR: In this paper, the effects of different porous microstructures on the PZT 95/5/2Nb was examined in detail, and a baseline material, similar to materials used in previous studies, was examined.
Abstract: Although the particular lead zirconate/titanate composition Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 (PZT 95/5–2Nb) was identified many years ago as a promising ferroelectric ceramic for use in shock-driven pulsed power supplies, relatively few studies have been performed to characterize its response under shock wave compression. The current study began when strong interest developed in numerically simulating the operation of pulsed power supplies, which required improved models for dynamic material properties. Experiments were conducted on a gas-gun facility to determine Hugoniot states, to examine constitutive mechanical properties during shock propagation, and to investigate shock-driven depoling kinetics. This article summarizes results from the first two of these areas. A baseline material, similar to materials used in previous studies, was examined in detail. Limited experiments were conducted with other materials to investigate the effects of different porous microstructures. Reverse-impact experiments wer...

Journal ArticleDOI
TL;DR: In this article, tungsten-bronze ferroelectrics were synthesized and characterized in the BaO-Sm2O3-TiO2-Nb2O5 system.

Journal ArticleDOI
TL;DR: In this paper, the fracture mechanics of piezoelectric solids were investigated and the influence of electric fields on the fracture toughness of ferroelectric ceramics and the derivation of an appropriate fracture criterion.
Abstract: This paper deals with the fracture mechanics of piezoelectric solids. All investigations consider a single crack, which is exposed to combined electrical and mechanical loading. The main subject of interest is the influence of electric fields on the fracture toughness of ferroelectric ceramics and the derivation of an appropriate fracture criterion. Numerical techniques are presented, allowing for the calculation of fracture quantities, i.e. stress intensity factors and energy release rates, once the piezoelectric field problem has been solved for arbitrary crack configurations using the finite element method. In order to describe a possible shielding of the crack tip due to ferroelectric/elastic domain switching events, a micromechanical model has been developed, based on a closed form solution of the piezoelectric field problem. In order to verify the theory, fracture experiments on barium titanate DCB specimens have been evaluated and compared to predictions of the model.

Journal ArticleDOI
TL;DR: In this paper, the low-field dielectric response of the relaxor-ferroelectric (1−x)PbFe2/3W1/3O3-PbTiO3 ceramics with various x, was investigated with empirical laws that describe the diffuse phase transitions in relaxors.
Abstract: The low-field dielectric response of the relaxor-ferroelectric (1−x)PbFe2/3W1/3O3–xPbTiO3 ceramics with various x, was investigated. The permittivity data were analyzed with empirical laws that describe the diffuse phase transitions in relaxors. A change of the character of the phase transition was found with increasing x, from a total diffuse, characteristic of relaxors, to a sharp one, typical of ferroelectrics. The deviations from the Curie–Weiss law of the dielectric constant data in the paraelectric phase were used to calculate a local order parameter within a modified-Landau theory for relaxors. The nonzero values of the local order parameter far above the Curie region indicate the thermal stability of the polar nanoregions in the relaxor state. The temperature dependence of the local order parameter clearly shows the evolution of the system from a short range ordered to a long range ordered ferroelectric, with increasing the PbTiO3 addition.

Journal ArticleDOI
TL;DR: In this article, the Euler-Lagrange equation for inhomogeneous polarization was solved analytically in both paraelectric and ferroelectric phases, and the temperature and size dependence of the spontaneous polarization and dielectric susceptibility of nanomaterials was obtained.
Abstract: The theory of size effects in nanocrystalline ferroelectric ceramics or nanoparticle powders allowing for surface tension and depolarization field is proposed. Surface tension was included in the free energy functional and extrapolation length was expressed via surface tension coefficient. The latter was shown to be dependent on temperature due to its relation to the dielectric permittivity of the nanoparticles. The depolarization field effect was calculated in the model taking into account the space-charge layer on the surface. The Euler–Lagrange equation for inhomogeneous polarization was solved analytically in both paraelectric and ferroelectric phases. The temperature and size dependence of the spontaneous polarization and dielectric susceptibility of nanomaterials was obtained. The possibility to calculate these and other properties by minimization of the conventional free energy in the form of different power polarization series, but with coefficients that depend on particle size, temperature, contribution of depolarization field and surface tension coefficient, was demonstrated. A comparison with available experimental data is performed.

Journal ArticleDOI
TL;DR: In this paper, a field effect transistor was constructed with a ferromagnetic (La,Ba)MnO3 channel and a ferroelectric PbZr0.2Ti0.8O3 gate insulator with the aim of controlling the metal-insulator transition at room temperature.
Abstract: We have constructed field-effect transistor structures that consist of a ferromagnetic (La,Ba)MnO3 channel and a ferroelectric PbZr0.2Ti0.8O3 gate insulator with the aim of controlling the metal–insulator transition at room temperature by applying an electric field. Investigations have revealed that the transition temperature changed from 237.0 K to 242.0 K for the La0.90Ba0.10MnO3 channel layer by ferroelectric remnant polarity (±50 μC/cm2) and from 280.5 K to 283.0 K (±26 μC/cm2) for the La0.85Ba0.15MnO3 channel layer. These shifts, which are linearly proportional to the magnitude of ferroelectric remnant polarization, are induced by the accumulation charge due to the electric field.

Journal ArticleDOI
Bicai Pan, H. Yu, Di Wu, X. H. Zhou, J.-M. Liu 
TL;DR: In this paper, the dynamic hysteresis response of ferroelectric SrBi2Ta2O9 thin films versus periodically varying electric field over a frequency range of f=10−1-106 Hz and amplitude range of E0=15-158 kV/cm is measured utilizing the Sawyer-Tower method.
Abstract: The dynamic hysteresis response of ferroelectric SrBi2Ta2O9 thin films versus periodically varying electric field over a frequency range of f=10−1–106 Hz and amplitude range of E0=15–158 kV/cm is measured utilizing the Sawyer–Tower method. The dynamic order parameter Q shows anomalous behavior against the field amplitude, and a single-peaked hysteresis dispersion is identified. The field response of hysteresis area 〈A〉 in the form of 〈A〉∝f2/3E02/3 over the low frequency range is evaluated, while the response over the high frequency range takes the form of 〈A〉∝f−1/3E02. We demonstrate that the hysteresis dispersion spectrum exhibits single-parameter scaling, and predicts a characteristic time for domain reversal that is inversely correlated to the field amplitude.

Journal ArticleDOI
TL;DR: In this article, high-quality c-axis epitaxial ferroelectric thin films of Bi4Ti3O12 (BTO) and Nd-substituted BTO, Bi315Nd085Ti 3O12(BNT), were prepared on (001)-LaNiO3-coated (001) LaAlO3 substrates by pulsed-laser deposition.
Abstract: High-quality c-axis epitaxial ferroelectric thin films of Bi4Ti3O12 (BTO) and Nd-substituted BTO, Bi315Nd085Ti3O12 (BNT), were prepared on (001)-LaNiO3-coated (001) LaAlO3 substrates by pulsed-laser deposition The epitaxial alignments were established by the x-ray diffraction, including θ–2θ and φ scans Compared to the BTO films, the BNT films have significantly improved electrical properties with about 2 times larger remanent polarization, 06 times lower coercive field, better fatigue-resisting characteristics, and 17 times larger dielectric constant These results showed experimentally that Nd substitution could enhance the c-axis electrical properties of BTO The reason for the improved properties of BNT films was discussed

Journal ArticleDOI
TL;DR: The nanocrystalline Gd-doped lead titanium zirconate (PGZT) with the composition Pb092Gd008(Zr053Ti047)098O3 has been synthesized by a combination of high-energy ball milling [mechanical alloying (MA)] and sintering.
Abstract: The nanocrystalline Gd-doped lead titanium zirconate (PGZT) with the composition Pb092Gd008(Zr053Ti047)098O3 has been synthesized by a combination of high-energy ball milling [mechanical alloying (MA)] and sintering PGZT prepared by MA followed by high-temperature sintering has a higher dielectric constant compared to that of the conventional technique PGZT shows a nonrelaxor ferroelectric behavior but has diffuse ferroelectric–paraelectric phase transition The activation energy of the material was found sensitive to its crystallite size

Journal ArticleDOI
TL;DR: In this article, the asymptotic problem of a semi-infinite crack perpendicular to the poling direction in a ferroelectric ceramic subjected to combined electric and mechanical loading is analyzed to investigate effect of electric fields on fracture behavior.
Abstract: The asymptotic problem of a semi-infinite crack perpendicular to the poling direction in a ferroelectric ceramic subjected to combined electric and mechanical loading is analyzed to investigate effect of electric fields on fracture behavior. Electromechanical coupling induced by the piezoelectric effect is neglected in this paper. The shape and size of the switching zone is shown to depend strongly on the relative magnitude between the applied electric field and stress field as well as on the ratio of the coercive electric field to the yield electric field. A universal relation between the crack tip stress intensity factor and the applied intensity factors of stress and electric field under small-scale conditions is obtained from the solution of the switching zone. It is found that the ratio of the coercive electric field to the yield electric field plays a significant role in determining the enhancement or reduction of the crack tip stress intensity factor. The fracture toughness variation of ferroelectrics under combined electric and mechanical loading is also discussed.

Journal ArticleDOI
TL;DR: In this paper, the ferroelectricity of epitaxially grown lanthanide-substituted Bi4Ti3O12, (Bi4−xLnx)Ti 3O12 (Ln=La, Nd, and Sm) thin films with various lanthanides contents (x) was systematically investigated.
Abstract: The ferroelectricity of epitaxially grown lanthanide-substituted Bi4Ti3O12, (Bi4−xLnx)Ti3O12 (Ln=La, Nd, and Sm) thin films with various lanthanide contents (x) was systematically investigated; (104)-oriented epitaxial (Bi4−xLnx)Ti3O12 thin films were grown on (111)SrRuO3∥(111)SrTiO3 substrates by metalorganic chemical vapor deposition. The remanent polarization (Pr) increased with x irrespective of the kind of lanthanide element. The maximum Pr values were 17, 25, and 20 μC/cm2 for (Bi3.44La0.56)Ti3O12, (Bi3.54Nd0.46)Ti3O12, and (Bi3.87Sm0.13)Ti3O12 thin films, where the coercive field (Ec) values were 145, 135, and 135 kV/cm, respectively. Reduction in the Pr values due to the excess substitution of the lanthanide is considered to originate from the solubility limit of the lanthanide in the Bi site in the pseudoperovskite layer. The Nd-substituted film with the largest polarization is comparable to the commercially used Pb(Zr,Ti)O3 films and is a useful candidate for lead-free ferroelectric applications.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the relaxation motion and memory effect of domain structures using mechanical and dielectric loss measurements in BaTiO3 ceramics with grains sizes varied from 1 μm to 50 μm.
Abstract: The relaxation motion and memory effect of domain structures have been investigated using mechanical and dielectric loss measurements in BaTiO3 ceramics with grains sizes varied from 1 μm to 50 μm. The measurements of mechanical loss, elastic modulus, dielectric loss and permittivity show that each phase transition induces a loss peak and an anomaly in the dielectric constants and elastic modulus, furthermore, a number of relaxation loss peaks due to ferroelectric domains in the samples with large grain have been observed. All the relaxation peaks can be analysed by Arrhenius relationship for a wide range of frequency from 10−2 to 106 Hz. The activation energies of relaxation peaks have been determined as 0.92 eV, 0.68 eV, 0.47 eV, and 0.29 eV for the peaks located in the tetragonal, orthorhombic, and rhombohedral phase, with Arrhenius perfactor in the order of 10−13 s. Moreover, one relaxation process is insensitive to ferroelectric phase transitions, and it can exist in all the ferroelectric phases. This implies a possible memory effect of ferroelectric domain structures. Such a motion of domain wall is limited in fine-grained materials. Effect of vacuum annealing on the relaxation peak in the tetragonal phase is also studied to clarify the mechanisms of the peak. These relaxation peaks could be explained by the interaction between different domain walls and the diffusion of oxygen vacancy in the domains.

Journal ArticleDOI
TL;DR: In this article, a chemical-solution-deposition method was used to extract different Bi2O3 template layers for thin Ferroelectric (Bi,La)4Ti3O12 (BLT) thin films, and the results showed that the use of these template layers improved the P-E hysteresis loops of BLT thin films.
Abstract: Ferroelectric (Bi,La)4Ti3O12 (BLT) thin films with different Bi2O3 template layers were prepared on Pt/Ti/SiO2/Si substrates by a chemical-solution deposition method. The BLT films with a thin Bi2O3 bottom layer and those with a thin Bi2O3 intermediate layer had a (117) preferentially oriented growth after annealing at 750 °C, while those with a thin Bi2O3 upper layer and those without a Bi2O3 template layer exhibited a high c-axis orientation. The surface morphologies changed with different preferential orientations. The electrical measurements showed that the use of Bi2O3 template layers improved significantly the P–E hysteresis loops of BLT thin films. The remanent polarization (2Pr) and coercive field (Ec) values of BLT films without a Bi2O3 template layer, with a Bi2O3 upper layer, with a Bi2O3 bottom layer, and with a Bi2O3 intermediate layer annealed at 750 °C were 10.8, 29.12, 26.17, and 19.67 μC/cm2; 79.0, 74.5, 75.5, and 76.3 kV/cm, respectively, at an applied electric field of 350 kV/cm. The di...

Journal ArticleDOI
TL;DR: In this article, the effect of the B-site cation chemistry and ordering on the dielectric properties of solid solutions in the (1−x)Pb(Mg1/3Nb2/3)O3, Pb(Sc 1/2Nb1/2) O3 perovskite system was examined in samples with 0.1 ≤x≤ 0.9.
Abstract: The effect of the B-site cation chemistry and ordering on the dielectric properties of solid solutions in the (1−x)Pb(Mg1/3Nb2/3)O3–Pb(Sc1/2Nb1/2)O3 (PMN-PSN) perovskite system was examined in samples with 0.1 ≤x≤ 0.9. Thermal annealing treatments were effective in inducing long-range B-site order in the samples within this compositional range. The well-ordered, large chemical domain ceramics exhibit relaxor behavior up to x=∼0.5; for higher values of x, normal ferroelectric behavior was observed. For x≤ 0.5 reductions in the chemical domain, size had no significant effect on the weak-field dielectric properties, but induced a transition to relaxor behavior for x > ∼0.6. The disordered PSN-rich samples undergo a spontaneous zero-field relaxor to ferroelectric transition similar to that reported previously for PSN. The field-dependent properties of compositions lying closest to the relaxor to ferroelectric crossover exhibited the highest sensitivity to alterations in the chemical order. The properties of this system are consistent with a “random site” description of the 1:1 ordered Pb(β′1/2β1/2)O3 structure with β′= (Mg(2−2x)/3Nb(1−x)/3Scx) and β″= Nb.

Journal ArticleDOI
TL;DR: The influence of the electric field-induced AFE to FE phase transition on the piezoelectric and strain behavior was studied in this article, where Nd3+-doped lead strontium zirconate titanate ceramics, which were located near the tetragonal antiferroelectric and rhombohedral ferroelectric phase boundary, were prepared by tape casting and sintering.
Abstract: Undoped and 1–3 at. % Nd3+-doped lead strontium zirconate titanate ceramics, which were located near the tetragonal antiferroelectric (AFE) and rhombohedral ferroelectric (FE) phase boundary, were prepared by tape casting and sintering. The influence of the electric field-induced AFE to FE phase transition on the piezoelectric and strain behavior was studied. Attempts were made to increase the field-induced strain by Nd3+ doping and its effect on the dielectric properties. Room temperature resistivity was also measured and explained by the defects produced. An in situ x-ray diffraction technique was developed for direct observation of the unit cell dimensions associated with the field-induced AFE to FE phase transition. The results indicated that a change in unit cell volume was responsible for the large field-induced strain associated with the AFE–FE phase transition.

Journal ArticleDOI
TL;DR: In this paper, the electrical response of strontium titanate borosilicate glass ceramic system with bismuth oxide addition was studied in terms of contributions arising from different polarization processes occurring at glassy matrix, crystalline phases, glass to crystal interface region and blocking electrodes.

Journal ArticleDOI
TL;DR: In this paper, the microstructure and electrical properties of ultrathin BaTiO3 films (2-7 nm thick) have been studied by high resolution transmission electron microscopy.
Abstract: The microstructure and electrical properties of ultrathin BaTiO3 films (2–7 nm thick) have been studied. Multidomain structures having 180° domains and 90° domain boundaries were observed by high resolution transmission electron microscopy. The domains, which have a width as small as one unit cell, are mostly oriented in parallel to the film plane. The film exhibits ferroelectric behavior characterized by polarization hysteresis loops and Curie temperature. The leakage current, switching time, and fatigue characteristics of the films are also reported.