Texture and Symmetry Relationships in Piezoelectric Materials

2005 ◽  
Vol 495-497 ◽  
pp. 13-22 ◽  
Author(s):  
Thomas S. Key ◽  
Jacob L. Jones ◽  
William F. Shelley ◽  
Ben J. Iverson ◽  
Hsin Yu Li ◽  
...  
Keyword(s):  
High Performance ◽  
Domain Walls ◽  
Elevated Temperatures ◽  
Piezoelectric Materials ◽  
Texture Evolution ◽  
Lead Zirconate ◽  
Modeling Tools ◽  
X Ray ◽  
Area Detector ◽  
Wide Range

The anisotropy that is inherent to piezoelectricity is directly tied to the symmetry of domains within the crystals of polycrystalline piezoelectrics. Alloy design for these oxide materials is often focused on influencing pinning of domain walls in polycrystals that have been subjected to high fields and elevated temperatures to introduce the ‘poled’ condition from which most piezoelectric devices operate. We have investigated a wide range of these oxides consisting of single phases or mixtures of phases that may be all or partially piezoelectric in character. Crystal symmetries investigated include tetragonal, orthorhombic, rhombohedral and monoclinic with some phase transitions evolving during high-temperature processing or during poling. Materials investigated include a range of bismuth titanates, lead titanates, lead zirconate titanates and sodium niobates. A variety of texture evaluation techniques, including area detector x-ray diffraction, synchrotron x-ray sources, and neutron sources have been utilized along with Rietveld diffraction modeling tools to enable a deeper understanding of domain textures, domain texture evolution and synergistic relations between crystallographic textures and domain textures. This paper documents an understanding of texture and anisotropy in these materials, and provides insight on approaches to optimize textures for high performance in these materials and demonstrates how these tools can be used to evaluate processing variations from production of these materials.

A scanning Kelvin probe for synchrotron investigations: thein situdetection of radiation-induced potential changes

2011 ◽  
Vol 19 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Bekir Salgin ◽  
Dirk Vogel ◽  
Diego Pontoni ◽  
Heiko Schröder ◽  
Bernd Schönberger ◽  
...  
Keyword(s):  
High Performance ◽  
Structural Changes ◽  
Kelvin Probe ◽  
X Ray ◽  
Scanning Kelvin Probe ◽  
Wide Range ◽  
First Results ◽  
Radiation Induced ◽  
Set Up

A wide range of high-performance X-ray surface/interface characterization techniques are implemented nowadays at every synchrotron radiation source. However, these techniques are not always `non-destructive' because possible beam-induced electronic or structural changes may occur during X-ray irradiation. As these changes may be at least partially reversible, anin situtechnique is required for assessing their extent. Here the integration of a scanning Kelvin probe (SKP) set-up with a synchrotron hard X-ray interface scattering instrument for thein situdetection of work function variations resulting from X-ray irradiation is reported. First results, obtained on bare sapphire and sapphire covered by a room-temperature ionic liquid, are presented. In both cases a potential change was detected, which decayed and vanished after switching off the X-ray beam. This demonstrates the usefulness of a SKP forin situmonitoring of surface/interface potentials during X-ray materials characterization experiments.

PROXIMA 2A: A New Micro-focus Beamline for Macromolecular Crystallography

2014 ◽  
Vol 70 (a1) ◽  
pp. C1672-C1672
Author(s):  
Denis Duran ◽  
Sebastien Le Couster ◽  
Gavin Fox ◽  
Roger Fourme ◽  
Rob Meijers ◽  
...  
Keyword(s):  
High Performance ◽  
Protein Structures ◽  
Photon Flux ◽  
First Year ◽  
X Rays ◽  
Macromolecular Crystallography ◽  
Fluorescence Detector ◽  
Beam Position ◽  
X Ray ◽  
Area Detector

PROXIMA 2A is a new micro-focus and energy tunable beamline dedicated to biological macromolecular crystallography at Synchrotron SOLEIL. The beamline officially opened in March 2013, and its first year of user operation has yielded excellent results. The X-ray source is a powerful in-vacuum U24 undulator coupled to a cryo-cooled Si[111] channel-cut monochromator and a pair of focussing bimorph mirrors in Kirpatrick-Baez configuration. This combination delivers a photon flux of over 10**12 ph/s into a focal spot of 10 μm × 5 μm (H×V FWHM), which is tunable over 6 – 15 keV. The supports of the optical elements have been designed to minimise the effects of vibrations and thermal dilations on the X-ray beam position, which is stable to within 5 microns over a day. The experimental station consists of a high performance micro-diffractometer, a cryostream, an area detector (ADSC Q315r), and an X-ray fluorescence detector. The X-ray energies for MAD experiments are directly calibrated on the sample. A robot equipped with a large 9 uni-puck dewar (CATS Irelec) is available to users for the automated transfer and screening of cryo-cooled samples. The users launch their experiments via an MXCuBE interface [1], which permits the centering of the sample, collecting of diffraction images, recording of X-ray spectra and the transfer of samples. The X-ray diffraction data are of an excellent quality, and the users readily exploit the micro-focused X-rays to select the best zones of their crystals. The first year of results from users has yielded a variety of success stories including novel protein structures resolved from crystals as small as 5 microns, as well as those solved by SAD & MAD methods. The future perspectives include automated helical and grid scans, in situ plate screening and multi-crystal merging techniques.

Molecular Dynamics Simulations of Piezoelectric Materials for Energy Harvesting Applications

2014 ◽  
Vol 792 ◽  
pp. 54-64 ◽  
Author(s):  
Justin B. Haskins ◽  
Alper Kinaci ◽  
Tahir Çağın
Keyword(s):  
Molecular Dynamics ◽  
Lead Zirconate Titanate ◽  
Domain Walls ◽  
Piezoelectric Materials ◽  
Md Simulations ◽  
Lead Zirconate ◽  
Hysteretic Behavior ◽  
Saturated Polarization ◽  
Phase Transition Temperatures ◽  
Dynamics Simulations

The previously proposed polarizable charge equilibrium (PQEq) force field model is parameterized for studying lead titanate (PT), lead zirconate (PZ), and their alloys: lead zirconate titanate (PZT). Several molecular dynamics (MD) simulations are performed to assess the degree of accuracy of the model. The phase transition temperatures, which are generally inaccurate in MD, are shown to be similar to experimental measurements. Also, the calculation of the ferroelectric hysteretic behavior, including the spontaneous polarization, saturated polarization and coercive fields, with extended MD is shown to give a qualitatively correct comparison between PT and PZT. The accuracy of the electronic properties in PQEq leads to direct application to a range of interesting problems such as enhanced properties of piezo- and ferro-electric nanostructures and the kinetics of domain walls in these materials.

EXPERIMENTAL RESEARCH ON GAS FOIL BEARINGS WITH POLYMER COATING AT AN ELEVATED TEMPERATURE

Tribologia ◽  
2016 ◽  
Vol 267 (3) ◽  
pp. 217-227 ◽  
Author(s):  
Grzegorz ŻYWICA ◽  
Paweł BAGIŃSKI ◽  
Artur ANDREARCZYK
Keyword(s):  
Polymer Coating ◽  
High Performance ◽  
Elevated Temperatures ◽  
Dynamic Properties ◽  
Point Of View ◽  
Stable Operation ◽  
Foil Bearings ◽  
Thin Foils ◽  
Wide Range ◽  
Micro Turbine

As demand for high-performance fluid-flow machines (including micro-turbines) increases across the globe, new non-conventional bearing systems are needed. In the last years, specialized technical solutions involving the use of gas foil bearings have been progressively introduced. The application of carefully selected, thin foils as key parts of foil bearings ensures stable operation of the rotor, which is supported by such bearings, even at very high rotational speeds. The article discusses the tests performed on the foil bearings incorporating a friction relieving polymer coating. The research was conducted on an advanced test rig allowing the experiments to be run at high speeds and elevated temperatures, which is in conditions that are typical for micro-turbine operation. The measurements of bearing components’ temperature and vibration levels were carried out at various rotational speeds. The tested bearings were also assessed from the point of view of wear and durability. Conducted research demonstrated that the carefully selected materials that were used to manufacture foil bearings’ key components have successfully contributed to achieving reliable operation within a wide range of rotational speeds, providing very good dynamic properties for the rotor.

Micro X-ray diffraction (µXRD): a versatile technique for characterization of Earth and planetary materials

2007 ◽  
Vol 44 (9) ◽  
pp. 1333-1346 ◽  
Author(s):  
Roberta L Flemming
Keyword(s):  
Ccd Camera ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
Thin Sections ◽  
X Ray ◽  
Area Detector ◽  
Wide Range ◽  
Individual Grains ◽  
Planetary Materials

Recent developments in laboratory-based micro X-ray diffraction (µXRD) have extended X-ray examination of geomaterials to the microscopic level (50–500 µm), greatly expanding the applicability of XRD to mineralogy, petrology, materials, environmental, and planetary sciences. Laboratory-based µXRD has been accomplished using a Bruker™ D8 Discover diffractometer, having a sealed-tube Cu source, theta–theta geometry, Gobel mirror parallel optics with 50–500 µm collimation, and general area detector diffraction system (GADDS). A wide range of samples, including polished thin sections, electron probe microanalysis (EPMA) mounts, rock slabs, whole rocks, and powders have been examined with µXRD using a remote-controlled XYZ sample stage, with imaging by optical microscope monitor and charge-coupled device (CCD) camera. Individual grains in heterogeneous samples have been examined in situ, with little or no sample preparation. The two-dimensional GADDS preserves textural and crystallinity information (e.g., bioapatite) and easily discriminates between multiple phases of utility for synthetic or natural samples (e.g., mine tailings). In situ µXRD of minerals preserves spatial relationships, enabling study of orientational phenomena, such as strain-related mosaicity (giving “streaked” diffraction lines). Examples include strained quartz (La Malbaie quartzite, Quebec) and shocked clinopyroxenes (Shergottite NWA 3171). Mineral mapping has been demonstrated by reproducing exsolution textures of kamacite from taenite (Widmanstätten pattern) in the Toluca iron meteorite. Diffraction data obtained from single crystals (by the omega scan method) have enabled grain-by-grain correlation between unit cell (µXRD) and chemical composition (EPMA), as demonstrated by kimberlite indicator garnets. The examples shown herein demonstrate the breadth of information that can be obtained by µXRD of Earth and planetary materials.

scholarly journals EUV and Hard X-ray Hartmann Wavefront Sensing for Optical Metrology, Alignment and Phase Imaging

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 874
Author(s):  
Ombeline de La Rochefoucauld ◽  
Guillaume Dovillaire ◽  
Fabrice Harms ◽  
Mourad Idir ◽  
Lei Huang ◽  
...  
Keyword(s):  
High Performance ◽  
High Harmonic ◽  
Ultra Violet ◽  
Phase Imaging ◽  
Wavefront Sensors ◽  
X Ray ◽  
X Ray Imaging ◽  
Wide Range ◽  
Automatic Alignment ◽  
Euv Lasers

For more than 15 years, Imagine Optic have developed Extreme Ultra Violet (EUV) and X-ray Hartmann wavefront sensors for metrology and imaging applications. These sensors are compatible with a wide range of X-ray sources: from synchrotrons, Free Electron Lasers, laser-driven betatron and plasma-based EUV lasers to High Harmonic Generation. In this paper, we first describe the principle of a Hartmann sensor and give some key parameters to design a high-performance sensor. We also present different applications from metrology (for manual or automatic alignment of optics), to soft X-ray source optimization and X-ray imaging.

HipGISAXS: a high-performance computing code for simulating grazing-incidence X-ray scattering data

2013 ◽  
Vol 46 (6) ◽  
pp. 1781-1795 ◽  
Author(s):  
Slim T. Chourou ◽  
Abhinav Sarje ◽  
Xiaoye S. Li ◽  
Elaine R. Chan ◽  
Alexander Hexemer
Keyword(s):  
Refractive Index ◽  
High Performance ◽  
Multicore Processors ◽  
Grazing Incidence ◽  
Scattering Data ◽  
Simulation Code ◽  
X Ray ◽  
X Ray Scattering ◽  
Wide Range ◽  
Ray Scattering

This article describes the development of a flexible grazing-incidence small-angle X-ray scattering (GISAXS) simulation code in the framework of the distorted wave Born approximation that effectively utilizes the parallel processing power provided by graphics processors and multicore processors. The code, entitledHigh-Performance GISAXS, computes the GISAXS image for any given superposition of user-defined custom shapes or morphologies in a material and for various grazing-incidence angles and sample orientations. These capabilities permit treatment of a wide range of possible sample structures, including multilayered polymer films and nanoparticles on top of or embedded in a substrate or polymer film layers. In cases where the material displays regions of significant refractive index contrast, an algorithm has been implemented to perform a slicing of the sample and compute the averaged refractive index profile to be used as the reference geometry of the unperturbed system. A number of case studies are presented, which demonstrate good agreement with the experimental data for a variety of polymer and hybrid polymer/nanoparticle composite materials. The parallelized simulation code is well suited for addressing the analysis efforts required by the increasing amounts of GISAXS data being produced by high-speed detectors and ultrafast light sources.

scholarly journals Studies of Optical, Dielectric, Ferroelectric, and Structural Phase Transitions in 0.9[KNbO3]-0.1 [BaNi1/2Nb1/2O3−δ]

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 35
Author(s):  
Blanca Yamile Rosas ◽  
Alvaro A. Instan ◽  
Karuna Kara Mishra ◽  
S. Nagabhusan Achary ◽  
Ram S. Katiyar
Keyword(s):  
Phase Transitions ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Structural Phase ◽  
Cubic Phase ◽  
Structural Phase Transitions ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Wide Range

The compound 0.9[KNbO3]-0.1[(BaNi1/2Nb1/2O3−δ] (KBNNO), a robust eco-friendly (lead-free) ferroelectric perovskite, has diverse applications in electronic and photonic devices. In this work, we report the dielectric, ferroelectric, and structural phase transitions behavior in the KBNNO compound using dielectric, X-ray diffraction, and Raman studies at ambient and as a function of temperature. Analyses of X-ray diffraction (XRD) data at room temperature (rtp) revealed the orthorhombic phase (sp. Gr. Amm2) of the compound with a minor secondary NiO cubic phase (sp. Gr. Fm3m). A direct optical band gap Eg of 1.66 eV was estimated at rtp from the UV–Vis reflectance spectrum analysis. Observation of non-saturated electric polarization loops were attributed to leakage current effects pertaining to oxygen vacancies in the compound. Magnetization studies showed ferromagnetism at room temperature (300 K) in this material. XRD studies on KBNNO at elevated temperatures revealed orthorhombic-to-tetragonal and tetragonal-to-cubic phase transitions at 523 and 713 K, respectively. Temperature-dependent dielectric response, being leaky, did not reveal any phase transition. Electrical conductivity data as a function of temperature obeyed Jonscher power law and satisfied the correlated barrier-hopping model, indicating dominance of the hopping conduction mechanism. Temperature-dependent Raman spectroscopic studies over a wide range of temperature (82–673 K) inferred the rhombohedral-to-orthorhombic and orthorhombic-to-tetragonal phase transitions at ~260, and 533 K, respectively. Several Raman bands were found to disappear, while a few Raman modes such as at 225, 270, 289, and 831 cm−1 exhibited discontinuity across the phase transitions at ~260 and 533 K.

Growth and Characterization of a Combinatorial Array of Mixed-Phase Magnesium-Aluminum Thin-Film Alloys

2007 ◽  
Vol 1056 ◽  
Author(s):  
Charles Olk ◽  
Daad B. Haddad
Keyword(s):  
Elevated Temperatures ◽  
Mixed Phase ◽  
Al Alloy ◽  
Structural Components ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mg17al12 Phase ◽  
Wide Range ◽  
Compositional Characterization

ABSTRACTCombinatorial gradient-controlled sputter deposition has been employed to produce a library of 100 separate thin films with a wide range of Mg-Al alloy compositions. We have successfully isolated the â (Mg17Al12) phase in polycrystalline films for investigation. The presence of the â phase has been found to be desirable for increasing corrosion resistance; however, in structural components under tensile loading and/or at elevated temperatures, the â phase precipitates undergo coarsening which induces poor creep behavior in several common alloys. We have also synthesized amorphous Mg-Al and mixed-phase compositions as identified by X-ray diffraction measurements. Details of the growth procedure as well as structural and compositional characterization are presented.

A molecular perovskite solid solution with piezoelectricity stronger than lead zirconate titanate

Science ◽  
2019 ◽  
Vol 363 (6432) ◽  
pp. 1206-1210 ◽  
Author(s):  
Wei-Qiang Liao ◽  
Dewei Zhao ◽  
Yuan-Yuan Tang ◽  
Yi Zhang ◽  
Peng-Fei Li ◽  
...  
Keyword(s):  
Solid Solution ◽  
Lead Zirconate Titanate ◽  
High Performance ◽  
Piezoelectric Coefficient ◽  
Piezoelectric Materials ◽  
Lead Zirconate ◽  
Sensing Applications ◽  
Different Types ◽  
Potential Applications ◽  
Piezoelectric Devices

Piezoelectric materials produce electricity when strained, making them ideal for different types of sensing applications. The most effective piezoelectric materials are ceramic solid solutions in which the piezoelectric effect is optimized at what are termed morphotropic phase boundaries (MPBs). Ceramics are not ideal for a variety of applications owing to some of their mechanical properties. We synthesized piezoelectric materials from a molecular perovskite (TMFM)x(TMCM)1–xCdCl3 solid solution (TMFM, trimethylfluoromethyl ammonium; TMCM, trimethylchloromethyl ammonium, 0 ≤ x ≤ 1), in which the MPB exists between monoclinic and hexagonal phases. We found a composition for which the piezoelectric coefficient d33 is ~1540 picocoulombs per newton, comparable to high-performance piezoelectric ceramics. The material has potential applications for wearable piezoelectric devices.

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