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Samples of 0.65Pb(Mg_1/3Nb_2/3)O₃-0.35PbTiO₃ single crystal cut in three orientations <001>, <110>, <111> were supplied by H. C. Materials Corporation, Urbana, Illinois, U.S.A. The dielectric constant was first measured for these three samples with different orientations. It shows the samples are of high quality. Then we observed the hysteresis loops at different temperatures for these samples. From hysteresis loops we obtained the remnant polarization as a function of temperature. It is found that the remnant polarization changes with temperature rapidly in the temperature region from 80°C to 130°C. The displacement current without sustained applied electric field on it that is supposed to be proportional to the pyroelectric coefficient in different orientation was measured by a Picoammeter under no applied electric field and the comparison of the displacement current density with the pyroelectric coefficient was presented.

This research work is aimed at lowering the sintering temperature of 0.9PMN–0.1PT ceramics by adding oxide additives. The oxides used for this purpose were Bi₂O₃ and Li₂CO₃ with various amounts, following the formula of xBi₂O_3+yLi₂CO₃, where x+y = 10 mol% and x = 1, 3, 5 and the mixed oxide additive powders were then added to the dried powder of 0.9PMN–0.1PT with 1 wt% concentration. An excess PbO content of approximately 3 wtadded to all compositions to compensate the lead loss. After that, the mixed powders were pressed into pellets and subsequently sintered to form the ceramic samples. The results showed that the sintering temperature of 0.9PMN–0.1PT ceramics could be lowered down from 1250°C to 900–1000°C by the addition of small amount of the oxide additives, where the optimum composition was found in the sample with x : y = 1 : 9 at sintering temperature of 1000°C. Moreover, the densification, dielectric and ferroelectric properties of this sample remain acceptable in particular uses, promising positive future for reduction of lead loss from electrical and electronic industries.

In this study, the (1-x)Pb(Mg_1/3Nb_2/3)O_3-xPbTiO₃ (when x=0.1, 0.3 and 0.5) ceramics were prepared from PMN and PT powders by a mixed-oxide method. The dielectric properties of the ceramics were measured as functions of both temperature (-150–400°C) and frequency (100 Hz–1 MHz). The results indicated that the dielectric properties of pseudo-cubic phase 0.9PMN-0.1PT and tetragonal phase 0.5PMN-0.5PT ceramics followed that of relaxor and normal ferroelectric behaviors, respectively, while the dielectric behaviors of a near MPB phase 0.7PMN-0.3PT ceramic showed a mixture of normal and relaxor ferroelectric behaviors. In addition, the Curie temperature (T_C) increased with increasing PT contents, while the diffusivity decreased. This confirmed a gradual transition from a relaxor ferroelectric behavior in 0.9PMN-0.1PT to a normal ferroelectric behavior in 0.5PMN-0.5PT. The difference in dielectric behaviors was attributed to the structural symmetry of the ceramics.

Having high dielectric constants and large mechanical strain, relaxor materials are attractive to the application of actuators in electromechanical systems and elements for large and bright display of optical image where the lower operation voltage and larger deformation are required. In this paper, we study the dielectric properties of 0.9PMN-0.1PT thick films fabricated by a spin coating method. The thick film is prepared for the application of large and bright display elements of an optical-image. In this application a layer of PMN-PT is filled in a mold. The thickness of the layer in the device should be in tens or hundreds of micrometers. Therefore, we used spin-coading technique to make PMN-PT thick films. The thickness of the films fabricated with this method ranges from 70mm to 100mm which are suitable to this application. The samples were electroded with silver print and characterized by dielectric constant and loss measurements. The experimental results show that the dielectric loss is less than 2 percent and the dielectric constant is greater than 10 at the room temperature in the frequency ranging from 100Hz to 1.0 MHz. A comparison of the results with those of PZT thick films manufactured with the same method is also presented.

Thin films of single c-domain/single crystal (PbMg_1/3Nb_2/3O₃)_1-x(PbTiO₃)_x, x = 0–0.4 (PMNT) were heteroepitaxially grown on (001)SrTiO₃ and (001)MgO substrates by magnetron sputtering using a quenching process. The lattice parameters of the quenched PMNT thin films were almost the same to the bulk values independently to the lattice parameters of substrates. The quenched PMNT thin films showed stress free structural properties, although the crystal structure of thin films is modified from bulk PMNT. The electromechanical properties are the same to the bulk single c-domain single crystals.

Photoacoustic microscopy (PAM), due to its deep penetration depth and high contrast, is playing an increasingly important role in biomedical imaging. PAM imaging systems equipped with conventional ultrasound transducers have demonstrated excellent imaging performance. However, these opaque ultrasonic transducers bring some constraints to the further development and application of PAM, such as complex optical path, bulky size, and difficult to integrate with other modalities. To overcome these problems, ultrasonic transducers with high optical transparency have appeared. At present, transparent ultrasonic transducers are divided into optical-based and acoustic-based sensors. In this paper, we mainly describe the acoustic-based piezoelectric transparent transducers in detail, of which the research advances in PAM applications are reviewed. In addition, the potential challenges and developments of transparent transducers in PAM are also demonstrated.

We report the preparation of epitaxial La${}_{0.7}$Sr${}_{0.3}$MnO₃ thin films grown on (001)-oriented 0.72Pb(Mg${}_{1∕3}$Nb${}_{2∕3})$O₃-0.28PbTiO₃ substrates by the sol–gel technique. The phase structure, magnetic properties and magnetoresistance of the samples are investigated by using high solution X-ray diffraction, atomic force microscopy, physical property measurement system, respectively. The La${}_{0.7}$Sr${}_{0.3}$MnO₃ thin films display a well-defined hysteresis loop and typical ferromagnetism behavior at lower temperature. High magnetoresistance at 5T of 42% appears at 227K for La${}_{0.7}$Sr${}_{0.3}$MnO₃ thin film.

Electromechanical and dielectric properties of PMN–PT ferroelectric ceramics are investigated. In particular, dielectric response studies focus on the investigation of the influence of the DC applied electric field on the dielectric permittivity as a function of temperature and frequency. Results reveal an electric field driven dielectric anomaly in the dielectric permittivity curves, $𝜀(E)$, which in turn prevails in the whole ferroelectric phase region and continuously vanishes for temperatures near the paraelectric-ferroelectric phase transition temperature. A schematic model for the domains dynamics of the studied material is proposed taking into account the simultaneous contribution of both 90${}^{\circ }$ and 180${}^{\circ }$ domains walls.

A series of (100$-x)$Pb(Mg${}_{1/3}$Nb${}_{2/3})$O${}_3-x$PbTiO₃ (PMN$-x$PT, $x$= 24, 25, 26) ceramics were prepared by solid-state reaction technique using MgNb₂O₆ precursor. The results of the detailed characterizations reveal that the content of PT has negligible influence on the grain size, and all samples possess the perovskite structure. As the PT content increases, the samples changed from the normal ferroelectric phase to the ergodic relaxor state at room temperature. As a result, PMN–$x$PT ceramics are endowed with electro-strain of 0.08% at a relatively low electric field of 2 kV/mm, and effective piezoelectric coefficient of 320 pm/V was obtained. Simultaneously, the PMN–$x$PT ceramics have exceptional pyroelectric performance, exhibiting a high pyroelectric coefficient $p$$\sim$5.5 – 6.3 × 10${}^{-8}$ C⋅cm${}^{-2}$⋅K${}^{-1}$. This study demonstrates the great potential of PMN–$x$PT for piezoelectric and pyroelectric device applications.