Download or read book Optical Properties of Lead Magnesium Niobate lead Titanate PMN PT and Strontium Barium Niobate SBN Thin Films written by Ka-yi Chan and published by . This book was released on 2005 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of the Optical and Physical Properties of Lead Magnesium Niobate lead Titanate Ceramic written by Michael Christopher Wagner and published by . This book was released on 2020 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the range of applications for electro-optic materials continues to grow, so does the need to identify and characterize new materials with improved electro-optic responses. A promising electro-optic material which has yet to be widely utilized is Lead Magnesium Niobate-Lead Titanate (PMN-PT) ceramic. In an effort to better characterize and understand the material, this work employed FTIR spectroscopy to calculate the refractive index of PMN-PT over a wide range of optical frequencies. Through analysis of interference fringes, the dispersion curve is calculated between 10,500 cm1 and 1200 cm1 (approximately 955 nm and 8.3 Îơm) containing nearly two thousand data points with an assumed accuracy of three decimal places. Additionally, capacitance bridge analysis is used to characterize the effect of temperature on the dielectric constant of PMN-PT. Special attention is given to the relationship of refractive index and dielectric constant so that a temperature study of the dielectric constant can be used to infer additional physical characteristics of PMN-PT.
Download or read book Growth of Optical Quality Lead Magnesium Niobate lead Titanate Thick Films written by Kyle French and published by . This book was released on 2019 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Thickness and Surface Roughness on Ferroelectric Behavior of Lead Magnesium Niobate Titanate and Lead Indium Niobate Magnesium Niobate Titanate Single Crystal written by Samuel Taylor and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lead magnesium niobate-titanate, Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT), and lead indium niobate-magnesium niobate-titanate, Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) ferroelectric single crystals are widely used in current and next generation medical ultrasound devices for their high signal strength and high frequency capabilities. With technology innovations, single crystal elements in transducers have become small enough that geometry induced domain clamping can severely limit the dielectric properties of the material and must be taken into consideration. Previous work on single crystal PMN-PT and PIN-PMN-PT has demonstrated that a sample with geometries on the scale of the materials ferroelectric domain size will cause domain clamping. [1] Those studies only evaluated single crystals with polished surface finishes. During preparation of a crystal sample, machining stresses can cause permanent lattice distortions, inducing a surface dead layer, an area of distorted lattice near the surface that is no longer ferroelectric. [2] The geometry induced domain clamping study used samples with essentially no surface dead layer. In medical ultrasounds, the low acoustic impedance of human tissues requires impedance matching layers to be adhered to the crystal surface within the transducer in order to transition the sound wave from the high impedance crystal to the low impedance human tissue. Most bonding techniques require a crystal surface rougher than that obtained from a traditional polishing process. A rougher surface will have high stress introduced deeper into the part due to the machining process. This creates a surface dead layer where the lattice is permanently distorted and no longer exhibits ferroelectric behavior. This will reduce the percent volume of ferroelectric material in the part, reducing overall ferroelectric properties/behavior. In this study, commercial surface finish techniques, including ID saw, wire saw, rough surface grinding and fine surface grinding were used to prepare crystal samples of varying thickness to evaluate the thickness and surface roughness dependence of PMN-PT and PIN-PMT- PT single crystals dielectric properties and ferroelectric behavior. All the samples studied met current commercial matching layer adhesion requirements for surface roughness. The ferroelectric crystals were polarized under both DC and AC fields. Electrical properties were measured after DC poling and AC poling. AC poling response was measured to observe the polarization hysteresis behavior of each sample. The primary electrical properties of interest were the thickness mode electromechanical coupling coefficient (kt), strain free component of the relative dielectric permittivity ([epsilon]r) and the coercive field (Ec), as well as the general shape and evolution of the polarization hysteresis loop through multiple measurements. With the ID sawn, wire sawn and rough surface finishes, both PMN-PT and PIN-PMN-PT crystals exhibited thickness dependent domain impingement. PMN-PT samples showed decreased [epsilon]r and non-characteristic PE hysteresis below 350[mu]m thickness. Although PIN-PMN-PT samples showed degradation in the ferroelectric hysteresis loop at thicknesses just below bulk thickness, [epsilon]r was maintained for samples of at least 400[mu]m thickness. For both crystal compositions, the surface dead layer occupied enough volume to result in a measurable detrimental effect on poling and electrical properties. The effects of the surface dead layer on ferroelectric behavior of the crystal samples were similar to the dimensional pinning of domains in thin polished samples of PMN-PT. With similar surface preparation, PIN-PMN-PT crystals also exhibited low properties, unlike in a polished sample. Using a fine grind technique, thin samples of PIN-PMN-PT could be poled and still maintain normal bulk properties and polarization behavior. This research focused on crystals with compositions near the morphotrophic phase boundary (MPB). This study concluded that in commercially processed PIN-PMN-PT and PMN-PT crystal samples, the main contributing factor to domain impingement is the surface dead layer, not the part geometry. As the surface finish is improved, the lattice damage caused by machining stress is reduced, therefore reducing the depth of the surface dead layer into the sample and reducing the overall volume percent of the sample that cannot be poled. As surface machining techniques are refined, creating a smoother surface, geometry induced domain impingement starts to play a larger role in ferroelectric behavior.
Download or read book Structural and Optical Properties of Strontium Barium Niobate and Potassium Niobate Thin Films Prepared by Metalorganic Chemical Vapor Deposition written by Michael James Nystrom and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ceramic Abstracts written by and published by . This book was released on 2001 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Engineering Index Annual written by and published by . This book was released on 1993 with total page 2264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its creation in 1884, Engineering Index has covered virtually every major engineering innovation from around the world. It serves as the historical record of virtually every major engineering innovation of the 20th century. Recent content is a vital resource for current awareness, new production information, technological forecasting and competitive intelligence. The world?s most comprehensive interdisciplinary engineering database, Engineering Index contains over 10.7 million records. Each year, over 500,000 new abstracts are added from over 5,000 scholarly journals, trade magazines, and conference proceedings. Coverage spans over 175 engineering disciplines from over 80 countries. Updated weekly.
Download or read book Growth of Heteroepitaxial Single Crystal Lead Magnesium Niobate lead Titanate Thin Films on R plane Sapphire Substrates written by Madhana Sunder and published by . This book was released on 2009 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Growth of Lead Magnesium Niobate lead Titanate Single Crystals by Seeded Polycrystal Conversion written by Adam Matthew Scotch and published by . This book was released on 2002 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Relaxor-based ferroelectric single crystals of Pb(Mg1/3Nb 2/3)O3-PbTiO3 [PMN-PT] have been produced via the Seeded Polycrystal Conversion [SPC] technique. Polycrystalline precursors of PMN-PT are converted to single crystals by inducing the boundary of a seed crystal to migrate through a polycrystalline matrix. The quality of PMN-PT single crystals grown by SPC is directly influenced by the microstructure of the polycrystalline precursor. The goal of this work was to examine the factors that controlled the final microstructure of the matrix and grown single crystals and to characterize their effects on properties.
Download or read book Investigation of the Growth of Lead Magnesium Niobate and Lead Zinc Niobate Lead Titanate Solid Solution Single Crystals by the Bridgeman Technique written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: During this program the following milestones were achieved: (1) Developed a method for synthesizing near pyrochlore-free PMNT starting material for crystal growth using the Columbite process and Pb3O4. Pyrochlore-free starting material prevents the crystals from sticking to the walls of the Pt crucibles and thereby prevents some forms of cracking. An another important development was the use of commercial magnesium niobate that reduced the number of processing steps and time by 50%. (2) Measured the liquidus curve in the PMN-PT phase diagram system for the first time. (3) Grew the first large PNM and PMN 10PT single crystals from nonfluxed melts by the Bridgman method during the first year and had their properties measured. These crystals grew along the 111 direction, their fast growth axis and their properties were consistent with literature values, (4) Grew large, transparent one inch diameter boules of PMN-3PT and PMN-32PT crystals using seed crystals for evaluation of compositional and structural uniformity, crystalline defects, etc. Uniform axial and radial composition was found in one cm diameter boules but axial Ti concentration variations were over 10% in one inch diameter crystals. Samples have been submitted for property measurements and evaluation to NUWC, Tetrad, Washington State University, Penn State University, Hewlett Packard, Wilcoxon, etc. It was found that the properties of the tetragonal PMNT phase (greater than 35% Ti) were not as good as those for rhombohedral crystals.
Download or read book Electrical and Optical Properties of Barium Strontium Titanate Thin Films Prepared by Metalorganic Chemical Vapor Deposition written by Stephen R. Gilbert and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ELECTROMECHANICAL CHARACTERIZATION OF LEAD MAGNESIUM NIOBATE BASED THIN FILMS written by Smitha Shetty and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Lead Magnesium Niobate (PMN) is the most studied relaxor ferroelectric compound with cation order intimately interacting with nanoscale polar heterogeneities. In undoped bulk PMN, the cation order can hardly be changed, while the polar order is quite responsive to external stimuli (electric field and temperature). Moreover, PMN-based oxides are of technological importance, displaying strong piezoelectric effects, high electrostrictive strains, and unusually high dielectric permittivity. The local compositional heterogeneity associated with short-range ordering of Mg and Nb in PbMg1/3Nb2/3O3 (PMN) is correlated with its characteristic relaxor ferroelectric behavior. Fully-ordered PMN has not been prepared as a bulk material. This work reports the growth and characterization of thin film PMN heterostructures with long-range cation order. These films were grown at temperatures below 1073 K by artificially reducing the degree of disorder via synthesis of heterostructures with alternate layers of Pb(Mg2/3Nb1/3)O3 and PbNbO3, as suggested by the random-site model. 100-nm-thick, phase-pure films were grown epitaxially on (111) SrTiO3 substrates using alternate target timed pulsed-laser deposition of Pb(Mg2/3Nb1/3)O3 and PbNbO3 targets with 20% excess Pb. Selected area electron diffraction confirmed the emergence of (1/2, 1/2, 1/2) superlattice spots with randomly distributed ordered domains as large as ~150 nm. These heterostructures exhibited a dielectric constant of 800, loss tangents of ~0.03 and 2 x remanent polarization of ~11 C/cm2 at room temperature. Polarization-electric field hysteresis loops, Rayleigh data, and optical second-harmonic generation measurements are consistent with the development of ferroelectric domains below 140 K. Temperature-dependent permittivity measurements demonstrate reduced frequency dispersion compared to short range ordered PMN films. Although perfectly layered heterostructures could not be grown, the novelty of this work lies in achieving the highest cation order in PMN. Further, these engineered films exhibit a continuum between normal and relaxor ferroelectric behavior as a function of temperature. The dynamic nonlinear dielectric responses were also studied as a function of temperature and electric field for the PMN thin films with long- and short-range ordering. It was found that long-range ordering decreased the dispersion in the first and third harmonic displacement current relative to short-range ordered films. For both sets of films, a second harmonic component of the dielectric response was also detected. The phase angles of the higher harmonic responses were used to probe the continuum in ferroelectric- relaxor behavior in these films. At high temperatures (e.g. above the freezing temperature), the presence of nanopolar clusters is believed to cause the strong dispersion in the third harmonic response in both long range and short-range films. However, at lower temperatures, changes in the sign of 3 suggest long-range ferroelectric ordering, such that the response of mobile interfaces (believed to be domain walls) dominate the response. Additionally, miniaturization of PMN based ferroelectric films for actuator applications necessitates quantification of piezoelectric properties with scaling. A single beam laser interferometer based on a modified Mirau detection scheme with a vertical resolution of 5pm was developed for localized d33 measurements on patterned piezoelectric films. The tool provides high spatial resolution (2m), essential for understanding scaling and processing effects in piezoelectric materials. This approach enables quantitative information on d33, currently difficult in local measurement techniques such as piezoresponse force microscopy. The interferometer is built in a custom microscope and employs a phase lock-in technique in order to detect sub-Angstrom displacements. d33 measurements on single crystal 0.67PbMg0.33Nb0.67O3-0.33PbTiO3 and bulk PbZrTiO3-5A ceramics demonstrated agreement within
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2726 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrical and Optical Properties Of Lead Selenide Thin Films By Chemical Bath Deposition written by Dr. Dhananjay Narayan Gujarathi and published by Lulu.com. This book was released on with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1990 with total page 1022 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Growth Domain Structures and Nonlinear Optical Properties of Ferroelectric Lead Titanate Thin Films written by Wei-Yung Hsu and published by . This book was released on 1994 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dielectric Properties of Lead Magnesium Niobate written by James Wilmarth Smith and published by . This book was released on 1967 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
