Transparent Ferroelectric Ceramics Research Articles

Effect of DC poling on transparency and photoluminescence in Pr:PMN-PT transparent ceramics

Electric poling could significantly influence the transparency and the photoluminescence (PL) intensities in transparent ferroelectric PL ceramics. This work applied direct current (DC) poling on a highly transparent 0.75PMN-0.25PT:0.015Pr3+ ceramic, observed the domain configurations in a direction perpendicular to poling direction. Lamellar domains perpendicular to electric field were observed after poling and decreased the transmittance by changing the propagation path of incident light. Besides, the enhancement of PL intensities by poling was found as high as 62 %, mainly due to the following reasons: the change of light propagation path by the lamellar domains is supposed to increase the absorption of exciting light; and the reduced crystal symmetry may increase the PL efficiency. This work revealed the effects of DC poling on transparency and PL properties in transparent ferroelectric PL ceramics.

Photostriction effect and electric properties of La-doped PMN-PT transparent ferroelectric ceramics

ABSTRACT Ferroelectric ceramics display a remarkable photostriction effect, which could facilitate the prevention of electromagnetic interference and promote the integration and miniaturization of actuator systems, indicating potential applications in glimmer sensors. In this work, highly transparent La-doped 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 (0.9PMN–0.1PT) ceramics were synthesized using a solid-state reaction method in an oxygenated atmosphere. XRD and SEM were used to analyze the phase structure of the dense samples, which displayed a pure perovskite structure, with no trace of a pyrochlore phase. With La doping, the phase transition temperature shows a decreasing trend, and its dielectric constant could reach up to 20,000. The P-E loop of the samples was gradually refined into a straight line with an increase in the doping amount. After La doping, the transparency of the 0.9PMN–0.1PT ceramics was significantly enhanced and reached up to 61% at the near-infrared band. Finally, the photogenerated voltage and deformation of the La-doped 0.9PMN–0.1PT ceramics were investigated under ultraviolet light of various intensities. After 20 s of irradiation at an intensity of 800 mW/cm2, the maximum voltage and deformation, with values of 40 V and 250 nm, respectively, were both found in the 1%La-doped 0.9PMN–0.1PT ceramics.

A strategy for enhancing luminescence thermometry via Ta5+-triggered K0.5Na0.5NbO3: Er3+ transparent ceramics

Luminescence thermometry is a reliable approach for remote thermal sensing, and extensive studies have been devoted to designing a luminescence thermometer with heightened thermal sensitivity. Herein, we report a promising luminescence thermometric material, Ta5+-substituted K0.5Na0.5NbO3:0.003Er3+ transparent ferroelectric ceramics. The temperature sensing sensitivity is significantly improved by adjusting the concentration of Ta5+ in the material. Specifically, utilizing the fluorescence intensity ratio from the 2H11/2 and 4S3/2 thermally coupled states of Er3+ as a detecting signal within the temperature range of 273–543 K, an optimal maximum absolute sensitivity of 0.0058 K–1 and relative sensitivity of 0.0158 K–1 are achieved for K0.5Na0.5NbO3: 0.65Ta5+/0.003Er3+. Simultaneously, as the concentration of Ta5+ increase, a unique evolution of structural phase transitions is observed from orthorhombic to tetragonal and then to cubic. This is accompanied by an improvement in luminescence temperature sensing properties, and the best sensitivity is demonstrated in the cubic-phase region. Intriguingly, a huge change in infrared luminescence properties as a function of temperature is found around the structure transition temperature of the samples. These results indicate a promising potential for achieving highly sensitive thermometry or monitoring phase structure transitions through luminescence thermometry behavior in the K0.5Na0.5NbO3 host.

Structural quantification of polar/nonpolar phases of relaxor clusters in transparent ferroelectric ceramics

A dual-phase refinement protocol considering distinct amounts of polar/nonpolar phases reflecting the polar nano phases formation in two relaxor ferroelectric systems was performed. The samples of PLZT and PLMN-PT have shown a typical relaxor behavior with different freezing temperatures, and the amounts of the polar phase of the lack of ergodicity were obtained using structure parameters.

Effects of Ba(Mg1/3Ta2/3)O3 doping on phase structure, optical and electrical properties of (K0.5Na0.5)NbO3 transparent ferroelectric ceramics

Effects of Ba(Mg1/3Ta2/3)O3 doping on phase structure, optical and electrical properties of (K0.5Na0.5)NbO3 transparent ferroelectric ceramics

Photochromic and Electric Field-Regulating Luminescence in High-Transparent (K,Na)NbO3-Based Ferroelectric Ceramics with Two-Phase Coexistence.

Rare earth Tb3+ doped (K0.465Na0.465Li0.07)(Nb0.93Bi0.07)O3 (KNNLB-x%Tb) lead-free transparent ferroelectric ceramics were designed and prepared. The effects of Tb3+ on phase structure, microstructure, optical transmittance, photoluminescence, and photochromic behaviors were studied. Although two ferroelectric phases coexist, the optical transmittance can reach the high value of 74% in the visible light region because of the fine grains, dense ceramic microstructure, large optical energy band gap, and relatively high symmetry of coexisting ferroelectric phases. In addition, Tb3+ works as a luminescent center, and the reversible photochromic modulation is achieved by alternate stimulation of illumination and heat treatment. Meanwhile, the luminescence contrast can be improved under in situ electric field stimulation due to the easy change of lattice symmetry in coexisting ferroelectric phases. The generation of color centers after illumination and the local crystal field around the luminescent center caused by in situ electric field contributes to above phenomena. These ceramics exhibit the great potential in optical data storage and anticounterfeiting.

The Ba(Bi0.5Ta0.5)O3 modified (K0.5Na0.5)NbO3 lead-free transparent ferroelectric ceramics with high transmittance and excellent energy storage performance

The Ba(Bi0.5Ta0.5)O3 modified (K0.5Na0.5)NbO3 lead-free transparent ferroelectric ceramics with high transmittance and excellent energy storage performance

The piezoelectric properties of transparent 0.75Pb(Mg1/3Nb2/3)O3-0.25PbTiO3:Pr3+ ceramics

The enhancement of both transparency and piezoelectric properties in transparent ferroelectric ceramics is a challenge. In this work, we prepared transparent 0.75Pb(Mg1/3Nb2/3)O3-0.25PbTiO3:xPr3+ ceramics by oxygen atmosphere sintering together with hot pressing sintering. When x = 1.5 mol%, a transparency of 68% @ 900 nm (close to the theoretical value ~71%) was achieved, and the piezoelectric properties increased to twice as much as those in undoped ceramics (x = 0). The small average domain size (below 200 nm) that far below the visible light wavelength was believed to benefit light transmittance. Meanwhile, the minute amount of tetragonal component induced by Pr3+ irons, was supposed to be responsible for the improved piezoelectric properties. These merits make Pr3+-doped 0.75PMN-0.25PT transparent ceramics promising functional materials for transparent piezoelectric devices.

A strategy for high performance of energy storage and transparency in KNN-based ferroelectric ceramics

Lead-free transparent ferroelectric ceramics with superior energy storage properties are highly desirable for pulsed power technologies and the increased optical transparency demand. However, the transparency and energy storage density of lead-free bulk ceramics cannot meet the requirements of their wide applications due to the coarse microstructure and relatively low breakdown strength. In this study, a design strategy is proposed to optimize the energy storage characteristics and transparency of ceramics by introducing nanodomains, increasing the band gap energy and reducing the grain size. The results showed that submicron grain (0.21 μm) and large band gap energy (Eg = 3.21 eV) were achieved through the introduction of the second component Sr(Sc0.5Nb0.5)O3 (SSN). An excellent transparency of up to 84.5% in the near-infrared region (1378 nm), a high energy density (W) of ~4.42 J·cm−3 and an extremely small strain of ~0.022% were simultaneously achieved in the 0.825(K0.5Na0.5)NbO3-0.175Sr(Sc0.5Nb0.5)O3 (0.825KNN-0.175SSN) ceramics. These results revealed the potential applications of (K0.5Na0.5)NbO3-based ceramics for energy storage and provide a feasible approach of domain engineering to develop new lead-free energy storagetransparency materials.

A novel transparent material based on KNN ferroelectric ceramics

Highly transparent lead-free ceramics of La-doped KNN based were synthesized by conventional solid state reaction method and ordinary sintering process for the first time. The optical and electrical properties of the KNN based lead-free transparent ferroelectric ceramics were investigated in this work. The transparent ceramics exhibited a transparency as high as 60% for the infrared wavelength. Meanwhile, the electrical properties of the ceramics still maintained relatively high levels (d 33 = 55 pC/N, T c = 402 °C), suggesting that it should be a novel and promising lead-free material that used in a large variety of electro-optical devices.

Visible or Near-Infrared Light Self-Powered Photodetectors Based on Transparent Ferroelectric Ceramics.

Transparent ferroelectrics, with promising prospects in transparent optoelectronic devices, have unique advantages in self-powered photodetection. The self-powered photodetectors based on the photovoltaic effect have quicker responses and higher stability compared with those based on the pyroelectric effect. However, the ferroelectric ceramics previously applied are always opaque and have no infrared light-stimulated photovoltaic effect. Thus, it would be very meaningful to design photodetectors based on infrared light-stimulated photovoltaic effect and/or transparent ferroelectric ceramics. In this work, highly optical transparent pristine lead lanthanum zirconate titanate (PLZT) and band gap-engineered Ni-doped PLZT ceramics with excellent piezoelectric/ferroelectric properties were prepared by hot-pressing sintering. Stable and excellent photovoltaic performance was obtained for pristine PLZT and band gap-engineered PLZT. The value of short-circuit current density is at least 2 orders of magnitude larger than those in PLZT reported in previous works. The transparent PLZT and Ni-doped PLZT ferroelectric ceramics are applied as self-powered photodetectors for the first time for 405 nm and near-infrared light, respectively. The devices based on PLZT under 405 nm light exhibit high detectivity (7.15 × 107 Jones) and quick response (9.5 ms for rise and 11.5 ms for decay), and those devices based on Ni-doped PLZT, under near-infrared light filtered from AM 1.5 G simulated sunlight, also exhibit high detectivity (6.86 × 107 Jones) and short response time (8.5 ms), both presenting great potential for future transparent photodetectors.

Induced Phase Transition in PbMg1/3Nb2/3O3–xPb(Zr0.53Ti0.47)O3 Transparent Ceramics

Time dependences of permittivity and optical transmission in the Pb(Mg1/3Nb2/3)O3–xPb(Zr0.53Ti0.47)O3 (x = 16, 23, and 33%) transparent ferroelectric ceramics are studied in the electric fields of 0 < E< 6 kV/cm. It is shown that even in fields, which are less than the coercive field, a sharp decrease in the permittivity occurs in compounds with x equal to 16 and 23% in a short time, while these changes in the ceramics with x = 33% are significantly smaller and occur over a longer time. It is found that the stability of the phase induced in the field after its switching-off significantly depends on the composition of studied ceramics: the higher the x value is, the more stable the induced phase. The observed difference in the time dependences of permittivity and stability of the induced phase in ceramics with different composition is explained by different sizes of ferroelectric domains.

Regulation of energy density and efficiency in transparent ceramics by grain refinement

Seeking for lead-free transparent ferroelectric ceramics with excellent recoverable energy storage density (Wrec) and high energy storage efficiency (η) is conducive to the development of transparent pulse capacitors for use in energy storage. In this work, we realized an effective grain size engineering via introducing a second component, namely, SrZrO3, into the K0.5Na0.5NbO3 (KNN) ceramics. Interestingly, the obtained submicron grains not only improve the transparency of the ceramics but also enlarge the breakdown field strength (Eb) and thus the Wrec. A good transparency of up to ~68% in the near-infrared region, an excellent Wrec of ~2.81 J·cm−3 and an extremely high η of ~80% were simultaneously achieved in the 0.91 K0.5Na0.5NbO3-0.09SrZrO3 (0.91KNN-0.09SZ) ceramics. The reduced grain and domain sizes, as well as the increased cation disorder, are believed to be responsible for the obtained narrow P-E loops and calculated large diffusion factor value (γ). This work provides a useful reference for developing KNN-based lead-free relaxor ferroelectric materials with both high energy storage properties and a good transparency.

Preparation and properties of multi-effect potassium sodium niobate based transparent ferroelectric ceramics

Traditional transparent materials, including glasses and polymers, are chemically unstable and mechanically weak. Single crystals of some inorganic materials are also optically transparent, which are more stable than glasses and polymers. The fabrication of crystals, however, is relatively slow. Fortunately, transparent ceramics emerge as a promising candidate. Transparent ferroelectric ceramic is a kind of transparent ceramic with electro-optic effect, which also has excellent characteristics of conventional ceramics with excellent mechanical properties, resistance to high temperature, resistance against corrosion, and high hardness. Lead based transparent ferroelectric ceramic dominates this field for many years due to its superior electro-optic effect. Owing to the high toxicity of lead oxide, however, its development is significantly hampered. Therefore, it is greatly urgent to develop the lead-free transparent ferroelectric ceramics with excellent properties to replace the traditional lead based ceramics. In this paper, (K&lt;sub&gt;0.5&lt;/sub&gt;Na&lt;sub&gt;0.5&lt;/sub&gt;)&lt;sub&gt;0.94–3&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;Li&lt;sub&gt;0.06&lt;/sub&gt;La&lt;i&gt;&lt;sub&gt;x&lt;/sub&gt;&lt;/i&gt;Nb&lt;sub&gt;0.95&lt;/sub&gt;Ta&lt;sub&gt;0.05&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; (KNLTN-La&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;; &lt;i&gt;x&lt;/i&gt; = 0, 0.01, 0.015, 0.02) lead-free transparent ferroelectric materials are fabricated by the conventional solid state reaction method and ordinary sintering process. The dependence of microstructure, phase structure, optical transmittance and electrical properties of the ceramic on composition are systemically investigated. The transparent ferroelectric ceramic with relaxor-behavior is obtained at &lt;i&gt;x&lt;/i&gt; = 0.02. The optical transmittance of the ceramic near infrared region is as high as 60%. Meanwhile, the electrical properties of the ceramic at &lt;i&gt;x&lt;/i&gt; = 0.01 still maintains a relatively high level (&lt;i&gt;d&lt;/i&gt;&lt;sub&gt;33&lt;/sub&gt; = 110 pC/N, &lt;i&gt;k&lt;/i&gt;&lt;sub&gt;p&lt;/sub&gt; = 0.267). In addition, the Curie temperature for each of all the samples is higher than 400 ℃. These results suggest that this material might be a novel and promising lead-free material that could be used in a large variety of electro-optical devices.

Индуцированный фазовый переход в прозрачной керамике PbMg-=SUB=-1/3-=/SUB=-Nb-=SUB=-2/3-=/SUB=-O-=SUB=-3-=/SUB=--xPb(Zr-=SUB=-0.53-=/SUB=-Ti-=SUB=-0.47-=/SUB=-)O-=SUB=-3-=/SUB=-

Abstract Time dependences of permittivity and optical transmission in the Pb(Mg_1/3Nb_2/3)O_3 –x Pb(Zr_0 . 53Ti_0 . 47)O_3 ( x = 16, 23, and 33%) transparent ferroelectric ceramics are studied in the electric fields of 0 &lt; E &lt; 6 kV/cm. It is shown that even in fields, which are less than the coercive field, a sharp decrease in the permittivity occurs in compounds with x equal to 16 and 23% in a short time, while these changes in the ceramics with x = 33% are significantly smaller and occur over a longer time. It is found that the stability of the phase induced in the field after its switching-off significantly depends on the composition of studied ceramics: the higher the x value is, the more stable the induced phase. The observed difference in the time dependences of permittivity and stability of the induced phase in ceramics with different composition is explained by different sizes of ferroelectric domains.

Anomalies in the Complex Parameters of the Transparent Ferroelectric Ceramics PLZT Near the Diffused Phase Transition

The main objectives of the paper were to study the anomalies in the electrophysical parameters of the transparent ferroelectric ceramics of the PLZT (X/65/35) system near the diffuse phase transition, and to measure the complex sets of dielectric, elastic and piezoelectric parameters of those materials over a wide frequency range. The ferroelectric ceramics of the system (Pb1-xLax)(Zr0,65Ti0,35)O3 with lanthanum content were chosen as the object of the study. The experimental samples of ferroelectric PLZT ceramics were obtained by the hot pressing method. The complex parameters of the experimental samples were measured by the piezoelectric resonance analysis method using the software package PRAP. The sets of complex elastic, dielectric and piezoelectric parameters of PLZT (6.5/65/35) ceramics were obtained. The anomalies in the behavior of surface acoustic waves velocity and attenuation for PLZT (7.5/65/35) ceramics near the temperature of diffused phase transition were found and discussed.

Synthesis and properties of La-doped PMN–PT transparent ferroelectric ceramics

Transparent ferroelectric ceramics 0.88Pb(Mg1/3Nb2/3)O3–0.12PbTiO3 (0.88PMN–0.12PT) with different La-doping concentrations (0.5, 1.0, 1.5 and 2.0 mol%) were fabricated via solid-state reaction and two-stage sintering. The effects of La-doping on the microstructure and electrical properties of the 0.88PMN–0.12PT ceramics were investigated. All the La-doped 0.88PMN–0.12PT ceramics exhibit pure perovskite phase with extremely dense microstructure and high optical transmittance. Among them, the 1.0 mol% La-doped ceramics show the highest transparency around 70% in near-infrared region, which is very close to its theoretical transmittance and basically meet the requirement on the transparency of electro-optical applications. The remanent polarization Pr, coercive field Ec, emax, the temperatures Temax corresponding to emax of the 0.88PMN–0.12PT ceramics decreased, and the relaxor behavior enhanced apparently with increasing La-doping concentration, which may ascribe to the fact that the substitution of Pb2+ ions by La3+ions reduces the long-range coupling of BO6 octahedrons.

Lead‐free (K,Na)NbO3‐based ceramics with high optical transparency and large energy storage ability

AbstractHighly transparent lead‐free (1‐x)K0.5Na0.5NbO3–xSr(Zn1/3Nb2/3)O3 (KNN–xSZN) ferroelectric ceramics have been synthesized via a conventional pressureless sintering method. All samples are optically clear, showing high transmittance in the visible and near‐infrared regions (~70% and ~80% at 0.5 mm of thickness, respectively). This exceptionally good transmittance is due to the pseudo‐cubic phase structure as well as the dense and fine‐grained microstructure. In addition, a high energy storage density of 3.0 J/cm3 has been achieved for the 0.94K0.5Na0.5NbO3–0.06Sr(Zn1/3Nb2/3)O3 ceramics with submicron‐sized grains (~136 nm). The main reason is likely to be the typical relaxor‐like behavior characterized by diffuse phase transition, in addition to the dense and fine‐grained microstructure. This study demonstrates that the 0.94K0.5Na0.5NbO3–0.06Sr(Zn1/3Nb2/3)O3 ceramic is a promising candidate of lead‐free transparent ferroelectric ceramics for new areas beyond transparent electronic device applications.

Fatigue properties and impedance analysis of potassium sodium niobate–strontium titanate transparent ceramics

Highly transparent ferroelectric ceramics based on 0.9K0.5Na0.5NbO3–0.1SrTiO3 were prepared using a pressure-less solid-state sintering method without using hot isostatic pressing and spark plasma sintering. An independence electromechanical response of bipolar switching cycles (S33 only degraded 3.2 % up to 107 cycles) was presented in this transparent ceramics, which indicated an extremely stable property under electric field. From impedance spectroscopy and X-ray photoelectron spectroscopy analyses, it was concluded that such optical transparency and fatigue-resistant behaviors were mainly attributed to the lower density of oxygen vacancies in the ceramics.

Multifuncional translucent ferroelectric Ba1−xCaxTiO3 ceramics produced by laser sintering

Multifunctional transparent ferroelectric ceramics can be used in a wide range of applications, such as optical modulation and image memory devices, optical shutters, switchers, etc. Frequently, electro-optical ceramics are lead-based and have the disadvantages of being harmful to the environment. For this reason, continuous effort has been done in the research for lead-free optical transparent ferroelectric ceramics. In this work, we have successfully sintered bulk lead-free translucent and nanostructured Ba1−xCaxTiO3 (X=0–0.30) ceramics by the laser sintering technique. In this technique, a CO2 laser is used as the main heating source for sintering. The laser-sintered ceramics presented high relative density, suitable ferro- and dielectric properties, transmittance up to 42% at 950nm for Ba0.70Ca0.30TiO3 sample and average grain size changing from 420nm to 600nm when the Ca concentration increases.