A5071368546- Ferroelectric and Piezoelectric Materials
- Acoustic Wave Resonator Technologies
- Multiferroics and related materials
- GaN-based semiconductor devices and materials
- Solid-state spectroscopy and crystallography
- ZnO doping and properties
- Integrated Circuits and Semiconductor Failure Analysis
- Advanced Electron Microscopy Techniques and Applications
- Ultrasonics and Acoustic Wave Propagation
- X-ray Diffraction in Crystallography
- Physics of Superconductivity and Magnetism
- Ga2O3 and related materials
- Electronic and Structural Properties of Oxides
- Magnetic Properties and Applications
- Atomic and Subatomic Physics Research
- Advanced X-ray Imaging Techniques
- Photorefractive and Nonlinear Optics
- Electron and X-Ray Spectroscopy Techniques
- Advanced Electrical Measurement Techniques
- Metal and Thin Film Mechanics
- Superconducting and THz Device Technology
- Renal and related cancers
- Nanowire Synthesis and Applications
- Gold and Silver Nanoparticles Synthesis and Applications
- Biosensors and Analytical Detection
Euclid Techlabs (United States)
2020-2021
National Institute of Standards and Technology
2020-2021
University of Siegen
2013-2018
Forschungszentrum Jülich
2013
Institute for Basic Science
2007-2008
Kyung Hee University
2007-2008
University of Minnesota
1976-1978
University of Minnesota System
1970
Abstract Structure-property relationships in ferroelectrics extend over several length scales from the individual unit cell to macroscopic device, and with dynamics spanning a broad temporal domain. Characterizing multi-scale structural origin of electric field-induced polarization reversal strain is an ongoing challenge that so far has obscured its fundamental behaviour. By utilizing small intensity differences between Friedel pairs due resonant scattering, we demonstrate time-resolved...
A 300 keV transmission electron microscope was modified to produce broadband pulsed beams that can be, in principle, between 40 MHz and 12 GHz, corresponding temporal resolution the nanosecond picosecond range without an excitation laser. The key enabling technology is a pair of phase-matched modulating de-modulating traveling wave metallic comb striplines (pulsers). An initial 30 ps achieved with strobe frequency 6.0 GHz. placement pulsers, mounted immediately below gun, allows for...
The aim of this contribution is to describe our recent development a novel compact field-programmable gatearray (FPGA)-based data acquisition (DAQ) system for use with multichannel X-ray detectors at synchrotron radiation facilities. designed time resolved counting single photons arriving from several-currently 12-independent detector channels simultaneously. Detector signals least 2.8 ns duration are latched by asynchronous logic and then synchronized the clock 100 MHz. incoming...
The relationship between crystal structure and physical properties in the ferroelectric Na 0.5 Bi TiO 3 (NBT) has been of interest for last two decades. Originally, average was held to be rhombohedral ( R c ) symmetry with a fixed polarization direction. This undergone series revisions, however, based on high-resolution X-ray diffraction, total neutron scattering, optical electron microscopy. recent experimental findings suggest that true is monoclinic (space group Cc ), which allows...
The physical origin of the piezoelectric effect has been focus much research work. While it is commonly accepted that origins piezoelectricity may be intrinsic (related to change lattice parameters) and extrinsic movement domain walls), their separation often a challenging experimental task. Here in situ high-resolution synchrotron X-ray diffraction combined with new data analysis technique characterize parameters microstructure PbZr 1− x Ti O 3 ( = 0.45) crystal under an external electric...
High piezoelectric activity of many ferroelectrics has been the focus numerous recent studies. The structural origin this remains poorly understood due to a lack appropriate experimental techniques and mixing different mechanisms related ferroelectricity ferroelasticity. Our work reports on study uniaxial ${\mathrm{Sr}}_{0.5}{\mathrm{Ba}}_{0.5}{\mathrm{Nb}}_{2}{\mathrm{O}}_{6}$ ferroelectric where formation regions with spontaneous strains is ruled out by symmetry interrelation between...
The time and frequency dependence of the electric field-induced phase transition in BaTiO3-BiZn1/2Ti1/2O3 was studied using situ X-ray diffraction. kinetics between cubic tetragonal phases described a modified Kolmogorov-Avrami-Ishibashi (KAI) equation. Unlike previous works, for which some assumptions (e.g., unimodal Gaussian) on distribution rates are needed, present work utilized Bayesian inference Markov chain Monte Carlo algorithm to obtain empirically without priori assumption...
A new data analysis routine is introduced to reconstruct the change in lattice parameters individual ferroelastic domains and role of domain-wall motion piezoelectric effect. Using special electronics for synchronization a PILATUS X-ray area detector with voltage signal generator, diffraction intensity distribution was measured around seven split Bragg peaks as function external electric field. The algorithm allows calculation `extrinsic' (related motion) `intrinsic' parameters)...
The design and testing of the new MAD-STROBO data acquisition system are reported. realizes stroboscopic collection high-resolution X-ray powder diffraction profiles under a dynamically applied electric field. It synchronizes an externally stimulus detected photons. feasibility detecting sub-millidegree shifts with microsecond time resolution is demonstrated. may be for investigation various macroscopic domain-related processes induced by external perturbation, such as elasticity or piezoelectricity.
The pyroelectric figures of merit p/ε, p/ε1/2 and p/(ε tan δ)1/2 are obtained from the measured data for triglycine sulfate (TGS) detectors results compared with predictions thermo-dynamic theory two-level theory. When one considers simplifying assumptions made in two theories, partial agreement is gratifying discrepancies understandable.
A new data acquisition system for in situ time-resolved three-dimensional reciprocal space mapping is reported. The based on a programmable microcontroller generating functional low-voltage signal, pixel area detector serving as master clock and high-voltage amplifier. Both Bragg diffuse scattering can be mapped large volume of under an alternating electric field pre-programmed shape. has been tested at the Swiss–Norwegian Beamline BM01 European Synchrotron by measuring dependence X-ray from...
With no low-temperature nucleation layers, heteroepitaxial GaN films were grown at 1050°C on c-plane sapphire substrates by hydride vapor phase epitaxy. Not like for the buffer upon island merging immediate smoothing of a surface was observed, but through several intermediate stages morphology evolved from three-dimensional islands to terrace-and-step structures. From synchrotron x-ray diffraction measurements, it revealed that density screw-or mixed-type threading dislocations greatly...
Abstract We report mitigation of electron-beam-induced radiation damage in biological macromolecules using rapid, low-dose transmission electron microscopy (TEM) with a new, tunable, retrofittable picosecond pulser. Damage strategies historically consisted sample cryoprotection and ultra-low beam current; ultrafast laser-pulsed systems have shown promise, but day-long acquisition times. show the first practical, fast, laser-free tunable system, diffraction series minutes at 5.2 GHz 10 pA....
Measurements are reported on the small signal complex dielectric constants ε' and ε'' (or tan δ) for thin samples of single crystal TGS, as functions frequency, degree poling, dc ac field strengths temperatures. The data strongly suggest that most effects caused by dynamic domain wall effects. At low fields there is an enormous dip in 6 between 10-20 kHz indicates almost complete absence any loss mechanism at frequency.
We investigated the phase diagram of Fe 2 O 3 (0001) surfaces with various terminations and catalytic mechanism CO oxidation on these using an ab initio thermodynamic method within density functional theory framework.
It is measured that tan S in unpoled triglycine sulfate varies as dγ where d the device thickness and 7 a constant slightly larger than 1/2. The observations can be interpreted by attributing dielectric losses to domain wall motions.
An abstract is not available for this content so a preview has been provided. As you have access to content, full PDF via the ‘Save PDF’ action button.
Changes in the polarization state of ferroelectric materials are mediated through motion planar defects such as domain walls. The interplay between two processes that enable inversion macroscopic materials, non-180° (domain reorientation) and 180° reversal), is not well understood. In this work, time-resolved x-ray diffraction was carried out during application an external electric field to investigate dynamic electric-field response mechanisms BaTiO3 (BT) BiZn1/2Ti1/2O3(BZT)-modified BT...
Electric-field-driven phase transformation phenomena in multiferroic BiFeO3 are directly linked to the functionalities of electronic devices based on materials. Understanding how evolves at nanoscale under influence an electric field will provide fascinating insights into key parameters that utilize features. Here, we report both electric-field-driven transient and permanent transformations highly strained thin films their dynamics nanoscale. We found two distinct were triggered below above...
Abstract GaN nanograins were grown on a c‐plane sapphire substrate and their strain relaxation due to x‐ray irradiation was investigated in‐situ by utilizing synchrotron xray scattering. The constantly exposed the X‐ray θ ‐2 scans through (002) Bragg peak of repeatedly carried out during irradiation. compressively strained gradually shifted toward higher angle, which implies that in compressive experienced (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)