Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 25 for “"PbTiO3"”.
-
Multiferroic Bismuth Ferrite-Lead Titanate and Iron-Gallium Crystalline Solutions: Structure-Property Investigations
… and properties of multiferrioic BiFeO3-x%PbTiO3 and Fe-x%Ga crystalline solutions were investigated. First, the results show that modified BiFeO3-PbTiO3 based ceramics have significantly enhanced multiferroic properties, relative to BiFeO3 single crystals. The data reveal: (i) a dramatic …
-
Structure prediction, growth, and characterization of perovskites
… the chemical reactions that govern growth of PbTiO3 and BiFeO3 by molecular-beam epitaxy. PbTiO3 and BiFeO3 are among two dozen complex oxides that are grown by MBE using thermodynamic composition control. I show that kinetics are also critical to growing phase-pure materials by this method, …
-
Multiscale Simulations of Dynamics of Ferroelectric Domains
… vector conservation. The model potentials for PbTiO3 and BiFeO3 are parameterized using the results from first-principles calculations. The bond-valence-based force field allows for molecular dynamics simulations of ferroelectric response at large time and length scale. The intrinsic inertial …
-
Magnetic and electric properties of bismuth ferrite lead titanate ceramics
… of multiferroic BiFeO3 doped with ferroelectric PbTiO3 (BFPT) can be prepared by conventional mixed oxide processing to produce a range of polycrystalline ceramics ranging throughout the xBiFeO3 - (1-x)PbTiO3 series. Sintered ceramics are shown to exhibit mixed tetragonal (P4mm) and rhombohedral …
-
Atomic layer deposition of binary and ternary lead and bismuth oxide thin films
… allowed processing of stoichiometric perovskite PbTiO3 and PbZrO3 thin films. Crystalline PbTiO3 on Si(100) was detected after annealing at 600 °C. In the case of lead zirconate, the perovskite phase (PbZrO3) was obtained on SrTiO3(100) after annealing at 600 °C. In both cases, a slight excess of …
-
Microstructure evolution and crystallisation kinetics of pure and isovalently substituted lead titanate thin films derived by chemical solution deposition
… perovskite materials based on lead titanate (PbTiO3) are especially relevant as functional layers in piezoelectric, ferroelectric, pyroelectric, and other devices. The industrially most important lead titanate derivative nowadays is Pb(Zr1-xTix)O3 (PZT). In order to enhance the efficiency of …
-
Ferroelectric materials with interfaces : first principles calculations
… of thin films of the perovskite ATiO3 compounds PbTiO3 and BaTiO3 is investigated. The investigations take advantage of the density functional theory (DFT), a modern theory which permits the treatment of the many electrons problem in real solids. The actual calculations are carried out with the …
-
The Freezing Mechanisms of Perovskite Relaxor Ferroelectrics and the Thermodynamic Stability of their Ferroelectric States
… the solid solution of PMN with the ferroelectric PbTiO3 (PT), (PbMg1/3Nb2/3O3 )1-x(PbTiO3 )x (x = 12%). To understand the onset of glassy freezing, we analyzed the effect of a DC external field Edc on the Vogel-Fulcher freezing temperature TVF. We found a reduction in TVF when the external field …
-
Ab initio investigation of layered and low-symmetry oxides and interfaces: multiferroic junctions, TCO’s, and a ferroelectric metal.
… interfa e magneto- ele tri e e ts of the SrRuO3/PbTiO3/SrRuO3 multi-ferroi tunnel jun tion (MFTJ) with asymmetri interfa es, by using standard DFT approa hes. A work about V doping of PbTiO3, a proper multiferroi ompound, is also presented. Se ond, an on-going work about a layered perovskite …
-
Emerging phenomena in oxide heterostructures
… the interface in SrTiO3/LaAlO3, EuO/LaAlO3, Fe/PbTiO3/Pt, Fe//BaTiO3/Pt and Cs/SrTiO3 heterostructures. We study the interplay between physical interactions, and quantify parameters that determine physical properties of hetetrostructures. These theoretical studies help understanding how physical …
-
Study of Functional Complex Oxides at High Pressure-Temperature Conditions
… compression and heating. Complementary work on PbTiO3 demonstrates how kinetic barriers and thermodynamic driving forces combine to stabilize unexpected dissociation products, including a previously unreported PbO polymorph at megabar pressures. High-entropy oxide nanoribbons were also examined, …
-
Kraftmikroskopische Untersuchungen dünner ferroelektrischer Filme
… of thin ferroelectric films of lead titanate (PbTiO3 : PTO), lead zirconium titanate (Pb(Zr0.25Ti0.75)O3 : PZT), and barium titanate (BaTiO3 : BTO) by means of scanning force microscopy - specifically Piezoresponse and Kelvin-Probe. The film thickness of the investigated samples ranged between …
-
Machining induced defects in Relaxor ferroelectric PMN-PT crystals
… single crystal {(1-x)[Pb(Mg1/3Nb2/3)O3]-x[PbTiO3] (PMN-PT)} under simulated process parameters for cutting speeds and down feeds. The machined surfaces are examined by non-contact optical profilometer for planarity and roughness, scanning electron microscopy for subsurface damage, and by …
-
All-electron GW calculations for perovskite transition metal oxides
… TMOs, for example the ferroelectrics BaTiO3 and PbTiO3, have become an integral part of present-day technologies. Intriguing properties of other perovskite TMOs such as ferromagnetic LaMnO(3+delta) or the high-k dielectric BaZrO3 and their potential use in future applications are currently …
-
Positron Annihilation Lifetime Spectroscopy Methodology and Application to Perovskite Oxide Materials
… was applied to a study on donor doping of PbTiO3 ceramics using a series of lanthanide-ions. It has been proposed that the smaller Ln-ions may act as amphoteric dopants substituting either on the A-site as a donor, or on the Bsite as an acceptor. In this study Ln-ions in size from La down …
-
Development of MRI-compatible Transducer Array for Focused Ultrasound Surgery: : The Use of Relaxor-based Piezocrystals
… in this work: Binary (x)Pb(Mg1/3Nb2/3) O3 - (1-x)PbTiO3 (PMN-PT) piezocrystal, and newly specialized FUS material, PZ54 ceramic. A characterization methodology was developed to fully characterize the materials of choice, under ambient and extreme conditions relevant to FUS applications. …
-
Aging and Barkhausen noise in the relaxor ferroelectrics
… relaxor PMN/PT (90/10) [(PbMn1=3Nb2=3O3)1¡x(PbTiO3)x, x = 0:1] shows aging that directly parallels that in re-entrant spin-glasses, with ""hole- like"" aging at low-temperature, where the uniaxial relaxor SBN:La (60/40) [Srx¡yLayBa1¡xNb2O6, x = 0:6; y = 0:01] shows cumulative, not …
-
Piezoelectric-based Multi-Scale Multi-Environment Energy Harvesting
… design. In the area of materials development, PbTiO3 (PTO) nanostructures consisting of nanofibers and three-dimensional (3-D) nanostructure arrays were hydrothermally synthesized. The growth mechanism of the PTO nanofibers and 3-D nanostructures were investigated experimentally and …
-
Magnetoelectric Thin Film Heterostructures and Electric Field Manipulation of Magnetization
… niobate-lead titanate, or Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT). This investigation revealed significant information on the structure-property relationships in crystals oriented at <110>, as well as shed light on the effect of ferroelectric phase transformation on magnetoelectric coupling. This …
Page 1 of 2