Lead Lanthanum Zirconate Titanate Research Articles

Multiple scattering and random walk based spectra modulation in Ho^3+/Tm^3+ codoped (Pb,La)(Ti,Zr)O_3 ceramics under plasma atmosphere

Remarkable enhancement of light emission in Ho3+/Tm3+codoped lanthanum lead zirconate titanate ceramics was investigated upon exposure to the plasma atmosphere. Photoinduced scatterers and weak localization of light played primary roles in these experimental results. Various long fading-off times were obtained and used to tune the light emission. An extreme sharp spike at 590 nm was detected, which originated from the variation and random lasing action of Ti4+ cations. These findings offer opportunities in designing new lasers, which might take advantages of rare earth elements and transitional metal activators in the same host materials.

High transmittance in lead-free lanthanum modified potassium-sodium niobate ceramics

Compared to lead lanthanum zirconate titanate (PLZT), potassium-sodium niobate shows good advances because of its excellent photoelectric response frequency and holographic storage. However, its low transmittance limits its application in photoelectrical controllers. To address this issue, lanthanum was introduced as a dopant, and the properties of the resulting ceramics were evaluated using both experimental and theoretical approaches. The (1-x)(K0.5Na0.5)NbO3-xLa2O3 (KNN-xL; x = 0.005, 0.010, 0.015, 0.020) transmittance ceramics were prepared by traditional low-pressure sintering process. Among the ceramics examined, KNN-0.015L achieved the widest band gap (Eg) of 3.108 eV and the highest transparency of 74%; both values are higher than those of PLZT (band gap = 3.10 eV, transparency = 70%) prepared by hot-press sintering. The transition rule was evaluated by density functional theory (DFT) to validate the experimental results obtained. Additionally, the related mechanism of transparency variation induced by electronic structure and grain size modulation was discussed thoroughly.

Synthesis and magnetoelectric properties of multiferroic composites of lead lanthanum zirconate titanate and mesoporous cobalt ferrite

We describe herein a facile synthetic approach to CoFe2O4 (CFO)/lead lanthanum zirconate titanate (PLZT) multiferroic composites. The composites were prepared by synthesizing mesoporous CFO through a novel temple-free strategy and subsequent generating PLZT inside mesoporous CFO. The coexistence of both CFO and PLZT phases in the composites was confirmed by XRD. The porosity and pore structures were determined from N2 physisorption analysis and TEM. The composites were found to possess multiferroicity at room temperature and a maximum magnetoelectric voltage coefficient of 36.7mV/cmOe. This work is anticipated to pave the way for enhancing the magnetoelectric coupling of multiferroic composite materials.

Closed-loop photovoltage control of lead lanthanum zirconate titanate ceramic for photovoltaic-electrostatic-driven servo system

A photovoltage closed-loop servo control model of lead lanthanum zirconate titanate ceramic is proposed for a photovoltaic-electrostatic-driven system in this article. The control equations of the proposed servo control model are derived based on the mathematical model of lead lanthanum zirconate titanate with coupled multi-physics fields. The parameters of photovoltage of lead lanthanum zirconate titanate ceramic during the illumination phase and light-off phase are identified through the static experiment. Then, photovoltage response of lead lanthanum zirconate titanate ceramic with simple on–off control strategy is numerically simulated based on the control equations presented in this article. After that, the closed-loop photovoltage control experiment based on single lead lanthanum zirconate titanate ceramic is carried out. The simulation and experimental results show that the photovoltage can be successfully controlled by switching the ultraviolet light with an optical shutter. The control strategy can be applied in the photovoltaic-electrostatic-driven servo system to achieve the target degree of angular or displacement deflection. In addition, closed-loop photovoltage control experiment of lead lanthanum zirconate titanate bimorph irradiated by double ultraviolet light is carried out to equip the system with the capacity of reverse voltage output.

A PLZT Novel Sensor with Pt Implanted for Biomedical Application: Cardiac Micropulses Detection on Human Skin

Advances in sensors for biomedical applications have been a great motivation. In this research, a PLZT (lead lanthanum zirconate titanate) novel sensor with platinum wire implanted in its longitudinal section was developed through of the synthesis process based on powder technology. The raw materials as lead (PbO), lanthanum (La2O3), zircon (ZrO2), and titanium (TiO2) were used in the formation of the chemical composition (62.8% PbO, 4.5% La2O3, 24.2% ZrO2, and 8.5% TiO2). Then, these powders were submitted to mix-mechanical milling at high energy; cylindrical samples with the implant of the platinum wire were obtained with the load application. Finally, the compacted samples were sintered at 1200°C for 2 hours, then followed by a polarization potential of 1500 V/mm at 60°C to obtain a novel sensor. The density and porosity were evaluated using the Archimedes’ principle, while the mechanical properties such as fracture toughness value and Young’s modulus were determined by indentation and ultrasonic methods, respectively. A microscopic examination was also carried out to investigate the structural properties of the material. The PLZT novel sensor is electronically arranged for monitoring the cardiac pulses through a data acquisition system. The results obtained in this research are analyzed and discussed.

Controllable photoinduced scattering and optimized light emission intensity in Nd3+ doped (Pb,La)(Zr,Ti)O3 perovskite ceramics

Controllable photoinduced scatterers were investigated in Nd3+-doped lead lanthanum zirconate titanate (PLZT) perovskite ceramics, the total number of which will increase dramatically with the induction of light intensity.

Low loss and high permittivity composites based on poly(vinylidene fluoride-chlorotrifluoroethylene) and lead lanthanum zirconate titanate

Lanthanum doped lead zirconate titanate stannate antiferroelectric ceramic (Pb0.97La0.02)(Zr0.63Sn0.3Ti0.07)O3 (PLZST) is proposed as an inorganic filler. P(VDF-CTFE)/PLZST composites with various compositions are fabricated via the solution cast process. The dielectric permittivity of the composites is significantly increased and the inherent loss is reduced in a wide range of frequencies at the same time. At 100Hz, the 40% PLZST loaded composite shows a dielectric permittivity of 28 (3 times more than that of the neat polymer), and a low loss of 0.045 (near half of that in the neat polymer). The low loss of the composite is most likely due to the slower increasing rate of the conductivity by comparison to the dielectric permittivity.

Transparent lead lanthanum zirconate titanate (PLZT) ceramic fibers for high-frequency ultrasonic transducer applications

This paper presents fabrication of transparent lanthanum zirconate titanate (PLZT) fibers using extrusion technique. The diameter of the sintered PLZT fiber is about 400-μm, and the fibers exhibit very good transparency. Measured dielectric constant, remnant polarization and coercive field of PLZT fiber were found to be 2340, 22.5-μC/cm2, and 9.8-kV/cm, respectively. The transparent piezoelectric materials may exhibit great potential for Photoacoustic (PA) imaging and hybrid intravascular imaging combining OCT and ultrasound imaging by using the transparent fiber as the path of light propagation and ultrasonic transducer material. In our study, these transparent PLZT fibers were designed to fabricate two types of high-frequency ultrasonic transducers: small aperture single PLZT fiber/epoxy composite and large aperture 1–3 PLZT fiber/epoxy composite ultrasonic transducers. Besides, a 20-μm tungsten wire phantom and the cornea of the porcine eye were also imaged with the 1–3 PLZT fiber/epoxy composite ultrasonic transducer to demonstrate its imaging capability.

Thickness effect on the structure, grain size, and local piezoresponse of self-polarized lead lanthanum zirconate titanate thin films

Polycrystalline lanthanum lead zirconate titanate (PLZT) thin films were deposited on Pt/TiO2/SiO2/Si substrates to study the effects of the thickness and grain size on their structural and piezoresponse properties at nanoscale. Thinner PLZT films show a slight (100)-orientation tendency that tends to random orientation for the thicker film, while microstrain and crystallite size increases almost linearly with increasing thickness. Piezoresponse force microscopy and autocorrelation function technique were used to demonstrate the existence of local self-polarization effect and to study the thickness dependence of correlation length. The obtained results ruled out the bulk mechanisms and suggest that Schottky barriers near the film-substrate are likely responsible for a build-in electric field in the films. Larger correlation length evidence that this build-in field increases the number of coexisting polarization directions in larger grains leading to an alignment of macrodomains in thinner films.

Electrostrictive effect for active control of surface plasmon signals.

Real-time surface plasmon modulation was achieved by electrically varying the pitch of a nanoscale surface relief diffraction grating inscribed on an azobenzene thin film covered with a layer of silver. The azobenzene film was spin coated on an electrostrictive Lead Lanthanum Zirconate Titanate (PLZT) ceramic substrate and a combination of DC bias and AC electric fields were applied longitudinally on the PLZT ceramic causing a change in the grating's pitch as well as the surface plasmon's resonance wavelength. This method permits extremely accurate control of the surface plasmon wavelength for tunable optics applications.

Excellent Transmittance Induced Phase Transition and Grain Size Modulation in Lead‐Free (1–x)(K0.5Na0.5)NbO3–xLaBiO3 Ceramics

A novel lead‐free excellent transmittance electro‐optic ceramics (1–x)(K0.5Na0.5)NbO3–xLaBiO3 (KNN‐LB, x = 0.000, 0.005, 0.010, 0.015, 0.020, 0.025, 0.040, 0.060) were fabricated by traditional pressureless ceramics processing procedure. The effects of LaBiO3 dopant concentration x on the microstructure, phase transition, optical property, and electrical properties were studied systematically. The X‐ray diffraction results indicated that the KNN‐LB ceramics with x ≥ 0.025 have the pseudocubic phase. The morphology, density, and microstructure of the KNN‐LB ceramics were characterized by scanning electronic microscopy and optical microscopy. In particular, the KNN‐LB ceramics (0.05 mm thickness) with x = 0.025 exhibited the highest transmittance of 74.00% in the visible spectrum comparable to the 72.00% transmittance of the lead lanthanum zirconate titanate (PLZT 9/65/35 of 0.127 mm thickness). In addition, the related mechanism of transparency variation induced by phase transition and grain size modulation were discussed thoroughly. Finally, the dielectric and ferroelectric properties of as‐prepared KNN‐LB ceramics were also investigated to further clarify the relationship between transparency and relaxor behavior.

PLZT-Based Shutters for Free-Space Optical Fiber Switching

With the increasing demand for optical fiber switching technologies from data center networks, shutter-based free-space optical fiber switching technology is promising for such network applications as the major advantages of this switching technology are that multicast switching, which is a vital functionality required in data center networks, can be easily achieved through its optical fan-out mechanism and that the switching performance can also be significantly strengthened while new materials with a faster response time are used as a spatial light modulator (SLM) to act as shutters. In this paper, the characteristics of ferroelectric liquid crystals and lead lanthanum zirconate titanate EO ceramic (PLZT) materials used as an SLM to act as shutters based on a type of strips for free-space optical fiber switching technology have been investigated. Although the PLZT-based shutters have a fundamental characteristic that a higher driving voltage might be required in order to provide a fast switching time less than a subnanosecond, with the use of a simple push–pull amplifier circuit design that can make a small input signal ride on a large dc voltage, the driving of a PLZT device in an optical switch can easily be achieved. Although the power consumption problem of this PLZT device resulting from a high driving voltage was not investigated in this paper, it can be effectively improved through a general boost converter that can be used to raise a small input dc voltage to a required higher driving voltage for the PLZT device. A proof of concept $1\times N$ , i.e., a 1 $\times$ 6 free-space optical fiber ribbon switching architecture capable of scaling to an $N\times N$ switching architecture for data center network application, was experimentally implemented to investigate the fiber array switching properties of PLZT-based shutters based on a type of strip. The experimental results show that the bit error rates estimated from the $Q$ -factor were all less than $10^{-9}$ and that the jitters were all less than 7.35% under a variety of shutter driving voltages at a link speed of 1 Gb/s and above.

Weak localization based enhancement of lasing emission under plasma atmosphere in Nd3+ doped (Pb,La)(Zr,Ti)O3 disordered ceramics

In this work, 1.5mol% Nd3+ doped lanthanum lead zirconate titanate (PLZT) ceramics were prepared, and excellent optical properties including wide transmission window, broad absorption peaks and large phonon energy were obtained in the materials. Disordered structure from grain to grain was characterized by scanning electron microscopy (SEM) and atomic forced microscopy (AFM). Obvious enhancement of lasing emission in the specimen was investigated upon exposing to plasma atmosphere. The enhancement factor almost remained stable along with the increase of pumping power. The photoinduced scatterers, random walks and weak localization of light played vital roles in the enhanced lasing emission. To verify the weak localization of light and random lasing action, experiments about enhanced backscattering cone of light and random lasing oscillation were performed. A tentative physical picture based on optical energy storage and increased scatterers was proposed to elucidate the experimental results. This result provides a new way to design multifunctional lasers, sensors and amplifiers.

Effect of Sintering Condition on Electrical Properties of PLZT Ceramics

Feroelectric lead lanthanum zirconate titanate (PLZT) ceramics 9/70/30 were synthesized by conventional mixed-oxide method via a vibro-milling technique. The effect of sintering temperature and two-stage sintering method on electrical properties of PLZT ceramics was investigated. The ceramic powder was uniaxially pressed in pellets and sintered at the temperatures ranging from 1200 to 1275 °C for 4hrs and two-stage sintering temperature at 1200 °C for 4 hrs. Dielectric, ferroelectric and strain properties of ceramics were characterized by LCR meter, modified Sawyer–Tower Circuit and modified Michelson interferometric technique respectively.

Research on the response improvement of optical actuation based on lead lanthanum zirconate titanate ceramics

Lead lanthanum zirconate titanate actuators taken as one type of photo-deformable actuators have been widely applied for micro-driven systems and active vibration control of photostrictive laminated flexible structures. However, the slow response of photodeformation of single patch lead lanthanum zirconate titanate actuator greatly affects its application. In this article, the main factors for the slow response of the lead lanthanum zirconate titanate actuator are investigated using experimental method. The increasing temperature during light on state and the residual photovoltage and photodeformation during light off state are considered as dominant factors causing the slow response of the lead lanthanum zirconate titanate actuator. To gain a better driving capability of lead lanthanum zirconate titanate actuator, some effective solutions through weakening the effect of increasing temperature and eliminating residual photovoltage and photodeformation are proposed and experimentally validated in this article. Considering the effective solutions proposed in this article, a novel optical driving mechanism based on multi-patches combination is proposed.

Effects of Zr/Ti Ratio on the Electric-Induced Light Scattering Performances of PLZT Transparent Ceramics

Lead lanthanum zirconate titanate (PLZT) transparent ceramics have attracted more and more attentions for their unique electric-induced light scattering effects. The PLZT ceramics of 7.45 mole% lanthanum with different Zr/Ti ratios (Zr/Ti=68/32, 69/31, 70/30, 71/29, 72/28) were prepared by the hot-press sintering method. The X-ray diffraction patterns confirm that all the PLZT samples are perovskite structure without detected secondary phases. The SEM images of the fracture surfaces of the samples show that all the PLZT materials tend to fracture transgranularly, and exhibit fully dense and uniform microstructures. All the samples with different Zr/Ti ratios present typical relaxation ferroelectric phase transition characteristics with square shaped hysteresis loops. Noticeably, all the original PLZT samples show an excellent transparency in the wavelength range from visible to near-infrared, and they will become opaque after an appropriate electric field experienced. The opaque sample can also recover to the transparent state when an inverse compatible electric field acts on it. The contrast ratio of the sample increases firstly and then decreases when the Zr/Ti ratio increases from 68/32 to 72/28 (λ=632.8nm). The PLZT (7.45/70/30) material shows a maximum contrast ratio, which makes it promising to apply in optical modulators.

Energy storage properties of nano-grained antiferroelectric (Pb,La)(Zr,Ti)O<sub>3</sub> films prepared by aerosol-deposition method

Antiferroelectric films of Sn doped Lead Lanthanum Zirconate-Titanate [(Pb, La)(Sn, Zr, Ti)O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> , Sn-PLZT] with nano-grains were fabricated by aerosol-deposition (AD). The AD process produced highly dense films without visible pores. The polarization-electric field hysteresis loop and the phase transition behavior of PLZT with Sn doping into the B-sites were characterized. The grain sizes of the AD Sn-PLZT films, which were on the nano-scale, were controlled by the annealing temperature. Regardless of the compositions, the films with the nano-grains by the AD process showed less hysteretic behavior and larger stored energy. The Pb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.97</sub> La <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.02</sub> (Zr <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.85</sub> Sn <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.13</sub> Ti <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.02</sub> )O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (PL-0.13) film deposited by AD and annealed at 750 °C for 1 h showed an energy storage capacity and efficiency of 13.0 J/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> and 78.9 %, respectively.

PLZT陶瓷在多能场耦合下的光致伸缩效应

To eliminate the hysteresis phenomenon between the photodeformation and the photovoltage of PLZT(Lead Lanthanum Zirconate Titanate)under the irradiation of high energy light,a novel photostrictive constitutive equation in multi-energy fields was established and the influence factors of the hysteresis phenomenon were investigated by experiments.Firstly,the light-thermal-electricelastic coupling mechanisms of the photostrictive effect under a lighting were analyzed theoretically and the constitutive relationship of photostrictive effect was established. After that,a novel constitutive equation was obtained by the derivation of anomalous photovoltaic effect,thermal effect,pyroelectric effect,thermal expansion effect and piezoelectric effect.Finally,the photostrictive constitutive equation was validated through the temperature screening test and photostrictive static experiments.Experimental results indicate that the temperature rise of PLZT ceramic is the mainreason of hysteresis phenomenon;and the variation trends of experiment curves are agreed well with the theoretical results,which confirms the reasonability of the theoretical model.Moreover,the photodeformation of the PLZT in the experiment takes about 10 sto reach saturation after eliminating the temperature rise.It shows that reducing the temperature rise effectively eliminates the hysteresis phenomenon and improves the response speed of photodeformation.The novel constitutive equation provides a theoretical basis for driving and controlling of PLZT ceramics.

Effect of Microwave Sintering on Electrical Properties of PLZT Ceramics

Lead lanthanum zirconate titanate(PLZT) powders synthesized by partial co-precipitation method were used to fabricate PLZT ceramics by conventional muffle furnace or by microwave muffle furnace. The crystal structure, microstructure, electrical properties of PLZT ceramics prepared by these two methods were investigated. The results show that the PLZT ceramics sintered by these two methods are pure perovskite structure. Microwave sintered PLZT ceramics possess smaller grain, more uniform size and less holes than do the conven tional prepared. The microwave sintering temperature is much lower than that by the conventional method, and the duration time is also much less, while the electrical properties of the ceramics sintered by these two methods are similar. The best properties of PLZT ceramics can be gained by microwave sintering at 1000℃ with dielectric constant and piezoelectric constant of 2512 and 405 p C/N. The remnant polarization is 16.5 k V/cm, and the coercive field is 8.2 μC/cm2. The dielectric constant and piezoelectric constant of PLZT ceramics sintered by conventional method at 1250 ℃reach the maximum values of 2822 and 508 p C/N. The remnant polarization is 21.6 k V/cm and the coercive field is 9.6 μC/cm2.

Compact, integrated PLZT optical switch array

Due to the excellent electro-optic properties of lead lanthanum zirconium titanate ((Pb,La)(Zr,Ti)O3, PLZT), compact 1×2 and 1×4 PLZT optical switches with a high response speed are proposed and fabricated successfully in this Letter. By introducing a thin isolating layer between the waveguides and the electrodes, the absorption loss of the fabricated 1×2 PLZT switch caused by the electrodes is reduced 8.9 dB with a relatively low driving voltage. The 1×2 PLZT switch shows an insertion loss of 18.3 dB and crosstalk of 20.5 dB at an applied voltage of 9.5 V. The fabricated 1×4 switch array shows an insertion loss of 20.7 dB and a crosstalk of 20.5 dB at an applied voltage of 13 V. The response time of the switches is less than 27 ns, and the device’s size is only 15 mm×6 mm. The switches can be used in optical communication systems.