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Your search keyword '"Hruszkewycz, S. O."' showing total 48 results
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48 results on '"Hruszkewycz, S. O."'

1. Extending the Takagi-Taupin equations for x-ray nanobeam Bragg coherent diffraction

Author

Zhou, T., Cherukara, M. J., Kandel, S., Allain, M., Hua, N., Shpyrko, O., Takamura, Y., Cai, Z., Hruszkewycz, S. O., and Holt, M. V.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We present a new approach for simulating x-ray nanobeam Bragg coherent diffraction patterns based on the Takagi-Taupin equations. Compared to conventional methods, the current approach can be universally applied to any weakly strained system including semi-infinite crystals that diffract dynamically. It addresses issues such as the curved wavefront and re-divergence of the focused incident beam. We show excellent agreement against experimental data on a strained La0.7Sr0.3MnO3 thin film on SrTiO3 substrate, and a path to extracting physical information using automatic differentiation.

Published
2024

2. A differentiable forward model for the concurrent, multi-peak Bragg coherent x-ray diffraction imaging problem

Author

Maddali, S., Frazer, T. D., Delegan, N., Harmon, K. J., Sullivan, S. E., Allain, M., Cha, W., Dibos, A., Poudyal, I., Kandel, S., Nashed, Y. S. G., Heremans, F. J., You, H., Cao, Y., and Hruszkewycz, S. O.

Subjects
Condensed Matter - Materials Science, Electrical Engineering and Systems Science - Signal Processing, Physics - Computational Physics
Abstract

We present a general analytic approach to spatially resolve the nano-scale lattice distortion field of strained and defected compact crystals with Bragg coherent x-ray diffraction imaging (BCDI). Our approach relies on fitting a differentiable forward model simultaneously to multiple BCDI datasets corresponding to independent Bragg reflections from the same single crystal. It is designed to be faithful to heterogeneities that potentially manifest as phase discontinuities in the coherently diffracted wave, such as lattice dislocations in an imperfect crystal. We retain fidelity to such small features in the reconstruction process through a Fourier transform -based resampling algorithm designed to largely avoid the point spread tendencies of commonly employed interpolation methods. The reconstruction model defined in this manner brings BCDI reconstruction into the scope of explicit optimization driven by automatic differentiation. With results from simulations and experimental diffraction data, we demonstrate significant improvement in the final image quality compared to conventional phase retrieval, enabled by explicitly coupling multiple BCDI datasets into the reconstruction loss function., Comment: 30 pages, 23 figures

Published
2022

3. Quantum well stabilized point defect spin qubits

Author

Ivády, Davidsson, J., Delegan, N., Falk, A. L., Klimov, P. V., Whiteley, S. J., Hruszkewycz, S. O., Holt, M. V., Heremans, F. J., Son, N. T., Awschalom, D. D., Abrikosov, I. A., and Gali, A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Applied Physics
Abstract

Defect-based quantum systems in in wide bandgap semiconductors are strong candidates for scalable quantum-information technologies. However, these systems are often complicated by charge-state instabilities and interference by phonons, which can diminish spin-initialization fidelities and limit room-temperature operation. Here, we identify a pathway around these drawbacks by showing that an engineered quantum well can stabilize the charge state of a qubit. Using density-functional theory and experimental synchrotron x-ray diffraction studies, we construct a model for previously unattributed point defect centers in silicon carbide (SiC) as a near-stacking fault axial divacancy and show how this model explains these defect's robustness against photoionization and room temperature stability. These results provide a materials-based solution to the optical instability of color centers in semiconductors, paving the way for the development of robust single-photon sources and spin qubits.

Published
2019
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4. Bragg Coherent Modulation Imaging: Strain- and Defect- Sensitive Single Views of Extended Samples

Author

Ulvestad, A., Cha, W., Calvo-Almazan, I., Maddali, S., Wild, S. M., Maxey, E., Duparaz, M., and Hruszkewycz, S. O.

Subjects
Condensed Matter - Materials Science
Abstract

Nanoscale heterogeneity (including size, shape, strain, and defects) significantly impacts material properties and how they function. Bragg coherent x-ray imaging methods have emerged as a powerful tool to investigate, in three-dimensional detail, the local material response to external stimuli in reactive environments, thereby enabling explorations of the structure-defect-function relationship at the nanoscale. Although progress has been made in understanding this relationship, coherent imaging of extended samples is relatively slow (typically requiring many minutes) due to the experimental constraints required to solve the phase problem. Here, we develop Bragg coherent modulation imaging (BCMI), which uses a modulator to solve the phase problem thereby enabling fast, local imaging of an extended sample. Because a known modulator is essential to the technique, we first demonstrate experimentally that an unknown modulator structure can be recovered by using the exit wave diversity that exists in a standard Bragg coherent diffraction imaging (BCDI) experiment. We then show with simulations that a known modulator constraint is sufficient to solve the phase problem and enable a single view of an extended sample that is sensitive to defects and dislocations. Our results pave the way for BCMI investigations of strain and defect dynamics in complex extended crystals with temporal resolution limited by the exposure time of a single diffraction pattern.

Published
2018

5. Chrono CDI: Coherent diffractive imaging of time-evolving samples

Author

Ulvestad, A., Tripathi, A., Hruszkewycz, S. O., Cha, W., Wild, S. M., Stephenson, G. B., and Fuoss, P. H.

Subjects
Condensed Matter - Materials Science
Abstract

Bragg coherent x-ray diffractive imaging is a powerful technique for investigating dynamic nanoscale processes in nanoparticles immersed in reactive, realistic environments. Its temporal resolution is limited, however, by the oversampling requirements of 3D phase retrieval. Here we show that incorporating the entire measurement time series, which is typically a continuous physical process, into phase retrieval allows the oversampling requirement at each time step to be reduced leading to a subsequent improvement in the temporal resolution by a factor of 2 to 20 times. The increased time resolution will allow imaging of faster dynamics and of radiation dose sensitive samples. This approach, which we call "chrono CDI", may find use in improving time resolution in other imaging techniques.

Published
2016
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6. High resolution three dimensional structural microscopy by single angle Bragg ptychography

Author

Hruszkewycz, S. O., Allain, M., Holt, M. V., Murray, C. E., Holt, J. R., Fuoss, P. H., and Chamard, V.

Subjects
Condensed Matter - Materials Science, Physics - Optics
Abstract

We present an efficient method of imaging 3D nanoscale lattice behavior and strain fields in crystalline materials with a new methodology -- three dimensional Bragg projection ptychography (3DBPP). In this method, the 2D sample structure information encoded in a coherent high-angle Bragg peak measured at a fixed angle is combined with the real-space scanning probe positions to reconstruct the 3D sample structure. This work introduces an entirely new means of three dimensional structural imaging of nanoscale materials and eliminates the experimental complexities associated with rotating nanoscale samples. We present the framework for the method and demonstrate our approach with a numerical demonstration, an analytical derivation, and an experimental reconstruction of lattice distortions in a component of a nanoelectronic prototype device., Comment: 16 pages, 8 figures, including Methods and Supplemental Section

Published
2015
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7. Supplemental Material for 'High Contrast X-ray Speckle from Atomic-Scale Order in Liquids and Glasses'

Author

Hruszkewycz, S. O., Sutton, M., Fuoss, P. H., Adams, B., Rosenkranz, S., Ludwig Jr., K. F., Roseker, W., Fritz, D., Cammarata, M., Zhu, D., Lee, S., Lemke, H., Gutt, C., Robert, A., Gruebel, G., and Stephenson, G. B.

Subjects
Condensed Matter - Materials Science
Abstract

This supplemental material gives additional detail on Experimental Methods and Hard X-ray FEL Source Characteristics, Calculation of Maximum Speckle Contrast, Extracting Contrast of Weak Speckle Patterns, Estimated Temperature Increase from X-ray Absorption, Split-Pulse XPCS Feasibility, and Sample Disturbance During Single Pulses., Comment: This is the supplemental material for arXiv:1207.2458 by the same authors entitled: "High Contrast X-ray Speckle from Atomic-Scale Order in Liquids and Glasses"

Published
2012

8. High Contrast X-ray Speckle from Atomic-Scale Order in Liquids and Glasses

Author

Hruszkewycz, S. O., Sutton, M., Fuoss, P. H., Adams, B., Rosenkranz, S., Ludwig Jr., K. F., Roseker, W., Fritz, D., Cammarata, M., Zhu, D., Lee, S., Lemke, H., Gutt, C., Robert, A., Gruebel, G., and Stephenson, G. B.

Subjects
Condensed Matter - Materials Science
Abstract

The availability of ultrafast pulses of coherent hard x-rays from the Linac Coherent Light Source opens new opportunities for studies of atomic-scale dynamics in amorphous materials. Here we show that single ultrafast coherent x-ray pulses can be used to observe the speckle contrast in the high-angle diffraction from liquid Ga and glassy Ni2Pd2P and B2O3. We determine the thresholds above which the x-ray pulses disturb the atomic arrangements. Furthermore, high contrast speckle is observed in scattering patterns from the glasses integrated over many pulses, demonstrating that the source and optics are sufficiently stable for x-ray photon correlation spectroscopy studies of dynamics over a wide range of time scales.

Published
2012
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14. General approaches for shear-correcting coordinate transformations in Bragg coherent diffraction imaging. Part I

Author

Maddali, S., primary, Li, P., additional, Pateras, A., additional, Timbie, D., additional, Delegan, N., additional, Crook, A. L., additional, Lee, H., additional, Calvo-Almazan, I., additional, Sheyfer, D., additional, Cha, W., additional, Heremans, F. J., additional, Awschalom, D. D., additional, Chamard, V., additional, Allain, M., additional, and Hruszkewycz, S. O., additional

Published
2020
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15. Quantum well stabilized point defect spin qubits

Author

Iv��dy, Davidsson, J., Delegan, N., Falk, A. L., Klimov, P. V., Whiteley, S. J., Hruszkewycz, S. O., Holt, M. V., Heremans, F. J., Son, N. T., Awschalom, D. D., Abrikosov, I. A., and Gali, A.

Subjects
Condensed Matter::Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), FOS: Physical sciences, Applied Physics (physics.app-ph), Physics - Applied Physics
Abstract

Defect-based quantum systems in in wide bandgap semiconductors are strong candidates for scalable quantum-information technologies. However, these systems are often complicated by charge-state instabilities and interference by phonons, which can diminish spin-initialization fidelities and limit room-temperature operation. Here, we identify a pathway around these drawbacks by showing that an engineered quantum well can stabilize the charge state of a qubit. Using density-functional theory and experimental synchrotron x-ray diffraction studies, we construct a model for previously unattributed point defect centers in silicon carbide (SiC) as a near-stacking fault axial divacancy and show how this model explains these defect's robustness against photoionization and room temperature stability. These results provide a materials-based solution to the optical instability of color centers in semiconductors, paving the way for the development of robust single-photon sources and spin qubits.

Published
2019

16. Bragg Geometry X-ray Coherent Diffraction Imaging: Know before you go

Author

Allain, Marc, Hruszkewycz, S. O., Chamard, Virginie, Coherent Optical Microscopy and X-rays (COMiX), Institut FRESNEL (FRESNEL), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Argonne National Laboratory [Lemont] (ANL), Ferrand, Patrick, and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [PHYS.COND] Physics [physics]/Condensed Matter [cond-mat], ComputingMilieux_MISCELLANEOUS, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience

Published
2018

18. Multimodal X-ray imaging of grain-level properties and performance in a polycrystalline solar cell

Author

Ulvestad, A., primary, Hruszkewycz, S. O., additional, Holt, M. V., additional, Hill, M. O., additional, Calvo-Almazán, I., additional, Maddali, S., additional, Huang, X., additional, Yan, H., additional, Nazaretski, E., additional, Chu, Y. S., additional, Lauhon, L. J., additional, Rodkey, N., additional, Bertoni, M. I., additional, and Stuckelberger, M. E., additional

Published
2019
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19. Towards ultrafast dynamics with split-pulse X-ray photon correlation spectroscopy at free electron laser sources

Author

Roseker, Wojciech, Hruszkewycz, S. O., Lehmkühler, F., Walther, M., Schulte-Schrepping, H., LEE, SOOHEYONG, Osaka, T., Strüder, L., Hartmann, R., Sikorski, M., Song, S., Robert, A., Fuoss, P. H., Sutton, M., Stephenson, G. B., and Grübel, G.

Subjects
Science, Physics::Optics, lcsh:Q, ddc:500, lcsh:Science, Article
Abstract

Nature Communications 9(1), 1704 (2018). doi:10.1038/s41467-018-04178-9, One of the important challenges in condensed matter science is to understand ultrafast, atomic-scale fluctuations that dictate dynamic processes in equilibrium and non-equilibrium materials. Here, we report an important step towards reaching that goal by using a state-of-the-art perfect crystal based split-and-delay system, capable of splitting individual X-ray pulses andintroducing femtosecond to nanosecond time delays. We show the results of an ultrafast hard X-ray Photon Correlation Spectroscopy experiment at LCLS where split X-ray pulses were used to measure the dynamics of gold nanoparticles suspended in hexane. We show how reliable speckle contrast values can be extracted even from very low intensity free electron laser(FEL) speckle patterns by applying maximum likelihood fitting, thus demonstrating the potential of a split-and-delay approach for dynamics measurements at FEL sources. This will enable the characterization of equilibrium and, importantly also reversible non-equilibrium processes in atomically disordered materials., Published by Nature Publishing Group, London

Published
2018
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21. Towards ultrafast dynamics with split-pulse X-ray photon correlation spectroscopy at free electron laser sources

Author

Roseker, W., primary, Hruszkewycz, S. O., additional, Lehmkühler, F., additional, Walther, M., additional, Schulte-Schrepping, H., additional, Lee, S., additional, Osaka, T., additional, Strüder, L., additional, Hartmann, R., additional, Sikorski, M., additional, Song, S., additional, Robert, A., additional, Fuoss, P. H., additional, Sutton, M., additional, Stephenson, G. B., additional, and Grübel, G., additional

Published
2018
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23. In-situ synchrotron x-ray studies of the microstructure and stability of In2O3 epitaxial films

Author

Highland, M. J., primary, Hruszkewycz, S. O., additional, Fong, D. D., additional, Thompson, Carol, additional, Fuoss, P. H., additional, Calvo-Almazan, I., additional, Maddali, S., additional, Ulvestad, A., additional, Nazaretski, E., additional, Huang, X., additional, Yan, H., additional, Chu, Y. S., additional, Zhou, H., additional, Baldo, P. M., additional, and Eastman, J. A., additional

Published
2017
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33. In-situ synchrotron x-ray studies of the microstructure and stability of In2O3 epitaxial films.

Author

Highland, M. J., Hruszkewycz, S. O., Fong, D. D., Thompson, Carol, Fuoss, P. H., Calvo-Almazan, I., Maddali, S., Ulvestad, A., Nazaretski, E., Huang, X., Yan, H., Chu, Y. S., Zhou, H., Baldo, P. M., and Eastman, J. A.

Subjects
*THIN films analysis, *THIN films spectra, *THIN film crystallography, *X-ray diffraction, *X-ray scattering, *MAGNETRON sputtering, *INDIUM compounds synthesis, *MICROSTRUCTURE
Abstract

We report on the synthesis, stability, and local structure of In2O3 thin films grown via rf-magnetron sputtering and characterized by in-situ x-ray scattering and focused x-ray nanodiffraction. We find that In2O3 deposited onto (0 0 1)-oriented single crystal yttria-stabilized zirconia substrates adopts a Stranski–Krastanov growth mode at a temperature of 850 °C, resulting in epitaxial, truncated square pyramids with (1 1 1) side walls. We find that at this temperature, the pyramids evaporate unless they are stabilized by a low flux of In2O3 from the magnetron source. We also find that the internal lattice structure of one such pyramid is made up of differently strained volumes, revealing local structural heterogeneity that may impact the properties of In2O3 nanostructures and films. [ABSTRACT FROM AUTHOR]

Published
2017
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34. X-ray Nanodiffraction of Tilted Domains in a Poled Epitaxial BiFeO3 Thin Film

Author

ARGONNE NATIONAL LAB IL, Hruszkewycz, S O, Folkman, C M, Highland, M J, Holt, M V, Baek, S H, Streiffer, S K, Baldo, P, Eom, C B, Fuoss, P H, ARGONNE NATIONAL LAB IL, Hruszkewycz, S O, Folkman, C M, Highland, M J, Holt, M V, Baek, S H, Streiffer, S K, Baldo, P, Eom, C B, and Fuoss, P H

Abstract

We present measurements of crystallographic domain tilts in a (001) BiFeO3 thin film using focused beam x-ray nanodiffraction. Films were ferroelectrically pre-poled with an electric field orthogonal and parallel to as-grown tilt domain stripes. The tilt domains, associated with higher energy (010) vertical twin walls, displayed different nanostructural responses based on the poling orientation. Specifically, an electric field applied perpendicular to the as-grown domain stripe allowed the domain tilts and associated vertical twin walls to persist. The result demonstrates that thin film ferroelectric devices can be designed to maintain unexpected domain morphologies in working poled environments., Published in Applied Physics Letters, v99 article ID 232903, 6 Dec 2011. Sponsored in part by DoE. Prepared in collaboration with the Department of Materials Science and Engineering, University of Wisconsin-Madison.

Published
2011

36. Single shot speckle and coherence analysis of the hard X-ray free electron laser LCLS

Author

Lee, Sooheyong, primary, Roseker, W., additional, Gutt, C., additional, Fischer, B., additional, Conrad, H., additional, Lehmkühler, F., additional, Steinke, I., additional, Zhu, D., additional, Lemke, H., additional, Cammarata, M., additional, Fritz, D.M., additional, Wochner, P., additional, Castro-Colin, M., additional, Hruszkewycz, S. O., additional, Fuoss, P. H., additional, Stephenson, G. B., additional, Grübel, G., additional, and Robert, A., additional

Published
2013
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38. High Contrast X-ray Speckle from Atomic-Scale Order in Liquids and Glasses

Author

Hruszkewycz, S. O., primary, Sutton, M., additional, Fuoss, P. H., additional, Adams, B., additional, Rosenkranz, S., additional, Ludwig, K. F., additional, Roseker, W., additional, Fritz, D., additional, Cammarata, M., additional, Zhu, D., additional, Lee, S., additional, Lemke, H., additional, Gutt, C., additional, Robert, A., additional, Grübel, G., additional, and Stephenson, G. B., additional

Published
2012
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45. High-resolution three-dimensional structural microscopy by single-angle Bragg ptychography

Author

Hruszkewycz, S. O., Allain, M., Holt, M. V., Murray, C. E., Holt, J. R., Fuoss, P. H., and Chamard, V.

Abstract

Coherent X-ray microscopy by phase retrieval of Bragg diffraction intensities enables lattice distortions within a crystal to be imaged at nanometre-scale spatial resolutions in three dimensions. While this capability can be used to resolve structure–property relationships at the nanoscale under working conditions, strict data measurement requirements can limit the application of current approaches. Here, we introduce an efficient method of imaging three-dimensional (3D) nanoscale lattice behaviour and strain fields in crystalline materials with a methodology that we call 3D Bragg projection ptychography (3DBPP). This method enables 3D image reconstruction of a crystal volume from a series of two-dimensional X-ray Bragg coherent intensity diffraction patterns measured at a single incident beam angle. Structural information about the sample is encoded along two reciprocal-space directions normal to the Bragg diffracted exit beam, and along the third dimension in real space by the scanning beam. We present our approach with an analytical derivation, a numerical demonstration, and an experimental reconstruction of lattice distortions in a component of a nanoelectronic prototype device.

Published
2017
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46. Octahedral rotations in strained LaAlO3/SrTiO3 (001) heterostructures.

Author

Fister, T. T., H. Zhou, Z. Luo, S. S. A. Seo, Hruszkewycz, S. O., Proffit, D. L., Eastman, J. A., Fuoss, P. H., Baldo, P. M., H. N. Lee, and D. D. Fong

Subjects
OXIDES, ELECTRONIC behavior control, X-ray scattering, ELECTRON gas, PEROVSKITE
Abstract

Many complex oxides display an array of structural instabilities often tied to altered electronic behavior. For oxide heterostructures, several different interfacial effects can dramatically change the nature of these instabilities. Here, we investigate LaAlO3/SrTiO3 (001) heterostructures using synchrotron x-ray scattering. We find that when cooling from high temperature, LaAlO3 transforms from the Pm...m to the Imma phase due to strain. Furthermore, the first 4 unit cells of the film adjacent to the substrate exhibit a gradient in rotation angle that can couple with polar displacements in films thinner than that necessary for 2D electron gas formation. [ABSTRACT FROM AUTHOR]

Published
2014
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47. Phase stabilization of δ-Bi2O3 nanostructures by epitaxial growth onto single crystal SrTiO3 or DyScO3 substrates.

Author

Proffit, D. L., Bai, G.-R., Fong, D. D., Fister, T. T., Hruszkewycz, S. O., Highland, M. J., Baldo, P. M., Fuoss, P. H., Mason, T. O., and Eastman, J. A.

Subjects
X-ray scattering, EPITAXY, MORPHOGENESIS, MORPHOLOGY, NANOSTRUCTURES, SYNCHROTRONS
Abstract

We observe that the high-temperature δ-phase of Bi2O3 is stabilized to room temperature by the epitaxial growth of nanostructures onto either (001)-oriented SrTiO3 or (001)p-oriented DyScO3 single crystal substrates. In addition, the morphology can be controlled by the miscut of the substrate. Synchrotron x-ray scattering observations at controlled temperatures and oxygen partial pressures reveal that the δ-Bi2O3 nanostructures are coherently strained to the substrates at room temperature. Annealing the nanostructures at 600 °C causes gradual conversion of the (001)-oriented δ-phase to an unidentified strain-relaxed phase. [ABSTRACT FROM AUTHOR]

Published
2010
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48. Multimodal X-ray imaging of grain-level properties and performance in a polycrystalline solar cell

Author

Ulvestad, A., Hruszkewycz, S. O., Holt, M. V., Hill, M. O., Calvo-Almazán, I., Maddali, S., Huang, X., Yan, H., Nazaretski, E., Chu, Y. S., Lauhon, L. J., Rodkey, N., Bertoni, M. I., and Stuckelberger, M. E.

Subjects
7. Clean energy
Abstract

Journal of synchrotron radiation 26(4), 1316 - 1321 (2019). doi:10.1107/S1600577519003606, The factors limiting the performance of alternative polycrystalline solar cells as compared with their single-crystal counterparts are not fully understood, but are thought to originate from structural and chemical heterogeneities at various length scales. Here, it is demonstrated that multimodal focused nanobeam X-ray microscopy can be used to reveal multiple aspects of the problem in a single measurement by mapping chemical makeup, lattice structure and charge collection efficiency simultaneously in a working solar cell. This approach was applied to micrometre-sized individual grains in a Cu(In,Ga)Se$_2$ polycrystalline film packaged in a working device. It was found that, near grain boundaries, collection efficiency is increased, and that in these regions the lattice parameter of the material is expanded. These observations are discussed in terms of possible physical models and future experiments., Published by Wiley-Blackwell, [S.l.]

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