A5040704545- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- Advancements in Solid Oxide Fuel Cells
- Magnetic properties of thin films
- Ferroelectric and Piezoelectric Materials
- Magnetic and transport properties of perovskites and related materials
- Electronic and Structural Properties of Oxides
- Fuel Cells and Related Materials
- Dielectric materials and actuators
- Quantum and electron transport phenomena
- High-pressure geophysics and materials
- Semiconductor materials and devices
- Geometric Analysis and Curvature Flows
- Catalysis and Oxidation Reactions
- Advanced Numerical Analysis Techniques
- Electrocatalysts for Energy Conversion
- Microwave Dielectric Ceramics Synthesis
- Superconductivity in MgB2 and Alloys
- Theoretical and Computational Physics
- Dielectric properties of ceramics
- Advanced Differential Geometry Research
- Rare-earth and actinide compounds
- High voltage insulation and dielectric phenomena
- Advanced Chemical Physics Studies
- Astrophysical Phenomena and Observations
American University of the Middle East
2019-2024
Missouri University of Science and Technology
2007-2024
Ankara University
2012-2021
University of Washington
1998-2018
Bartin University
2012-2017
King Abdullah University of Science and Technology
2011-2015
Marmara University
2014
Fatih University
2014
American Ceramic Society
2000-2010
University of Alberta
2003-2009
Novel dielectric nanocomposites composed of ferroelectric polymers and surface-functionalized TiO2 nanoparticles with comparable permittivities homogeneous nanoparticle dispersions are prepared characterized. Enhancements in electric displacement energy density at high fields demonstrated.
To explain the observed X-ray data in a black hole–accreting matter system and understand physical mechanisms behind QPOs, we have numerically modeled dynamical oscillation properties of shock cone formed around both slowly rapidly rotating Hartle–Thorne holes, resulting from mechanism Bondi–Hoyle–Lyttleton (BHL). According to numerical simulations, an increase quadrupole parameter leads decrease opening angle hole. A larger results more falling into hole within cone. The combination...
We report inelastic neutron scattering measurements at excitation energies $\ensuremath{\Elzxh}\ensuremath{\omega}\ensuremath{\sim}41$ meV in YB${\mathrm{a}}_{2}$C${\mathrm{u}}_{3}$${\mathrm{O}}_{7}$. separate magnetic and phonon contributions to the cross section by a detailed analysis of momentum dependence scattered intensity. The previously reported broad peak around $\mathbf{q}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}(\ensuremath{\pi}/a,\ensuremath{\pi}/a)$ normal state can be...
Polarized and unpolarized neutron triple-axis spectrometry was used to study the dynamical magnetic susceptibility $\chi^{\prime\prime}({\bf q},\omega)$ as a function of energy ($\hbar\omega$) wave vector (${\bf q}$) in wide temperature range for bilayer superconductor YBa$_2$Cu$_3$O$_{6+x}$ with oxygen concentrations, $x$, 0.45, 0.5, 0.6, 0.7, 0.8, 0.93, 0.95. The most prominent features spectra include spin gap superconducting state, pseudogap normal much-discussed resonance,...
Inelastic neutron scattering was used to study the wavevector- and frequency-dependent magnetic fluctuations in single crystals of superconducting YBa$_2$Cu$_3$O$_{6+x}$. The spectra contain several important features, including a gap state, pseudogap normal state much-discussed resonance peak. appearance determined from transport nuclear coincides with formation excitations. exchange energy associated has temperature doping dependences as well magnitude describe approximately electronic...
We use inelastic neutron scattering to demonstrate that at low temperatures, the frequency magnetic fluctuations in YBa_2Cu_3O_{6.6} ($T_c=62.7$ K) are incommensurate, being found positions displaced by $\pm\delta$ ($0.057\pm 0.006$ r.l.u.) along $[\pi,\pi]$ direction from wave vector $(\pi,\pi)$ associated with antiferromagnetic order of parent insulator, YBa_2Cu_3O_{6}. The dynamical susceptibility $\chi''(q,\omega)$ incommensurate increases on cooling below $T_c$, accompanied a...
We have measured quantitatively the temperature dependence of local distortions ${\mathrm{PbTiO}}_{3}$ crystals below and above structural ferroelectric phase transition, using x-ray absorption fine-structure (XAFS) measurements. Two probe atoms, Pb Ti, were used. The results analyzed by fitting parametrized theoretical XAFS spectra to experimental results. These measurements provide quantitative ``distortion parameters'' defined as difference between distance its nearest neighbor in actual...
The interface between the polymer and particle has a critical role in altering properties of composite dielectric. Polymer-ceramic nanocomposites are promising dielectric materials for many electronic power devices, combining high constant ceramic particles with breakdown strength polymer. Self-assembled monolayers electron rich or poor organophosphate coupling groups were applied to affect filler-polymer investigate this on behavior. potential influence properties, particular leakage...
We report a small angle neutron scattering study of the vortex lattice in Y${\mathrm{Ba}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$ magnetic fields $0.5\ensuremath{\le}H\ensuremath{\le}5$ T applied along and close to $c$ axis. Over entire field range, vortices form an oblique with two nearly equal constants 73\ifmmode^\circ\else\textdegree\fi{} between primitive vectors. Numerical calculations suggest that variations superconducting order parameter near core are important stabilizing this...
Neutron scattering has been used to measure the charge and spin structure in highly underdoped superconductor ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{6.35}$. Incommensurate static ordering is found that remains at high temperatures. The magnetic pattern complex with a resonance incommensurate observed low results clarify role of striped phases ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{6+x}$ superconductors.
Intraband and interband contributions to the current-driven spin-orbit torque in magnetic materials lacking inversion symmetry are theoretically studied using Kubo formula. In addition fieldlike ${\mathbf{T}}_{\mathrm{FL}}={\ensuremath{\tau}}_{\mathrm{FL}}\mathbf{m}\ifmmode\times\else\texttimes\fi{}{\mathbf{u}}_{\mathrm{so}}$ (${\mathbf{u}}_{\mathrm{so}}$ being a unit vector determined by of coupling), we explore intrinsic contribution arising from impurity-independent transitions producing...
Abstract The Rashba effect plays important roles in emerging quantum materials physics and potential spintronic applications, entailing both the spin orbit interaction (SOI) broken inversion symmetry. In this work, we devise asymmetric oxide heterostructures of LaAlO 3 //SrTiO /LaAlO (LAO//STO/LAO) to study STO with an initial centrosymmetric structure, symmetry is created by inequivalent bottom top interfaces due their opposite polar discontinuities. Furthermore, report observation a...
Polarized and unpolarized triple-axis spectrometry has been used to study an underdoped YBa_2Cu3O6.6. Our results indicate that spin excitations in the superconducting state are essentially same as those fully doped material except unusual 41 meV resonance is observed at 34.8 meV. The normal characterized by a weakly energy-dependent continuum whose temperature dependence shows clear signature of gap Tc. enhancement accompanied suppression magnetic fluctuations both higher lower energies.
Pulsed neutron spectroscopy is used to absolute measurements of the dynamic magnetic susceptibility insulating Y${\mathrm{Ba}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{6.15}$. Acoustic and optical modes, derived from in- out-of-phase oscillation spins in adjacent Cu${\mathrm{O}}_{2}$ planes, dominate spectra are observed up 250 meV. The modes appear first at 74\ifmmode\pm\else\textpm\fi{}5 Linear-spin-wave theory gives an excellent description data yields intralayer interlayer exchange...
Inelastic pulsed neutron scattering measurements on ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{6.95}$ single crystals indicate that the sample has a distinct a-$b$ plane anisotropy in oxygen vibrations. The Cu-O bond-stretching-type phonons, which are suspected to interact strongly with charge, simultaneously observed along and b directions due 7-meV splitting arising from orthorhombicity, even though is twinned. bond-stretching LO branch polarization (perpendicular chain) loses...
Interfacial covalent bonding is an effective approach to increase the electrical resistance of a polymer–particle composite charge flow and dielectric breakdown. A bifunctional tether reagent bonded inorganic oxide particle surface assists with dispersion within thermosetting epoxy polymer matrix but then also reacts covalently matrix. Bonding resulted in that maintained pure glass transition temperature, compared modified or unmodified dispersions lacked matrix, which depressed lower...