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Showing 1 to 11 of 11 for “"Morphotropic Phase Boundary"”.
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Computer Modeling and Simulation of Morphotropic Phase Boundary Ferroelectrics
Phase field modeling and simulation is employed to study the underlying mechanism of enhancing electromechanical properties in single crystals and polycrystals of perovskite-type ferroelectrics around the morphotropic phase boundary (MPB). The findings include: (I) Coherent phase decomposition near …
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Interplay Between the Lattice and Spin Degrees of Freedom in Magnetoelectric and Magnetic Materials
… was found at the edge of the so-called morphotropic phase boundary. Such enhancement was studied (at the microscopic level) and found to be related to the large enhancement in the electric susceptibility tensor at this morphotropic phase boundary. Furthermore, we investigate the …
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Temperature And Pressure Effects On Elastic Properties Of Relaxor Ferroelectrics And Thermoelectrics: A Resonant Ultrasound Spectroscopy Study
… The material undergoes a series of structural phase transitions with changes in temperature and the chemical composition. The work covered in this dissertation seek to gain insight into the phase diagram of PMN-PT using temperature and pressure dependence of the elastic properties. Single …
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Structural Study of Heterogeneous States in Lead-free NBT-based Single Crystals
… goal of investigating the mechanism coupling of morphotropic phase boundary (MPB) and the maximum property responses in A-site disordered perovskite Pb-free piezoelectric systems. Using the framework of polar nanoregions and adaptive phase theory, I sought to determine how the nanostructure of …
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New modalities for strain engineering of lead-free perovskite ferroelectric thin films
… as well as the presence of the so-called morphotropic phase boundary (MPB) ̶ a temperature-independent composition-driven structural instability that results in superior dielectric and piezoelectric properties. However, increasing environmental concerns are driving efforts towards the …
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Magnetic and electric properties of bismuth ferrite lead titanate ceramics
… mixed tetragonal (P4mm) and rhombohedral (R3c) phase perovskite distortions from 0.4 ≤ x < 0.75, where at x ~ 0.75 a morphotropic phase boundary exists and compositions x > 0.75 are entirely rhombohedral. From extensive use of neutron diffraction experiments, the phase coexistence is attributed …
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Structure-Property Relationships of Multifeorric Materials: A Nano Perspective
… All of these materials undergo at least two phase transformations with coupled thermodynamic order parameters. These transformations lead to complex domain wall behaviors, which are driven by electric fields (ferroelectrics), magnetic fields (ferromagnetics), or mechanical stress …
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Structural Investigations of Highly Strictive Materials
… a lower temperature rhombohedral ferroelectric phase. Nanoscale domain engineering mechanism was found to still work in NBT-x%BT system and a modified phase diagram was proposed based on domain observations. An increased intensity of octahedral in-phase tilted reflections and a decrease in the …
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New modalities of strain-based engineering of ferroelectrics: domain structure and properties of PbZr1-xTixO3 thin films
… gradients with the directive of generating phase competition and high-energy ferroelastic domain structures to enhance ferroelectric susceptibilities. We, for the first time, grow epitaxial thin films of PbZr1-xTixO3 across the compositional phase diagram, and show that the rate of strain …
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Einfluß der Korngröße auf die morphotrope Phasengrenze in Sol-Gel abgeleiteten Nd-dotierten PZT-Keramiken
… untersucht. Dabei war besonders die morphotrope Phasengrenze (MPG) rhomboedrisch-tetragonal von Interesse. Messungen der dielektrischen und ferroelektrischen Eigenschaften zeigten unterhalb einer Grenzkorngröße von etwa 1 µm einen starken Einfluß des Gefüges und führten zu der Annahme, daß sich …
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Local symmetry and polarization in relaxor-based ferroelectric crystals
Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2013-05-24T22:02:27Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Kim_KyouHyun.pdf: 4556380 bytes, checksum: 3dac9ee508db17f0bac12ef97b4d87d3 (MD5)