U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Bruce D. Ravel (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 52

Emission Ghost Imaging: reconstruction with data augmentation

February 1, 2024
Author(s)
Kevin J. Coakley, Heather H. Chen-Mayer, Bruce D. Ravel, Daniel Josell, Nikolai Klimov, Sarah Robinson, Daniel S. Hussey
Ghost Imaging enables 2D reconstruction of an object even though particles transmitted or emitted by the object of interest are detected with a single pixel detector without spatial resolution. This is possible because the incident beam is spatially

Flexible formulation of value for experiment interpretation and design

December 12, 2023
Author(s)
Matthew Carbone, Hyeong Jin Kim, Chandima Fernando, Shinjae Yoo, Daniel Olds, Howie Joress, Brian DeCost, Bruce D. Ravel, Yugang Zhang, Phillip Michael Maffettone
The challenge of optimal design of experiments pervades materials science, physics, chemistry, and biology. Bayesian optimization has been used to address this challenge but requires framing experimental campaigns through the lens of maximizing some

Lattice vibrations and the energy landscape of the isoelectronic semiconductor series CuBr, ZnSe, GaAs, and Ge: The special case of CuBr and its d-level chemistry

November 9, 2023
Author(s)
Joseph Woicik, Eric J. Cockayne, Eric L. Shirley, Igor Levin, Conan Weiland, Bruce D. Ravel, A. M. Milinda Abeykoon
We have examined the lattice vibrations and the energy landscape of the isoelectronic diamond and zincblende semiconductor series CuBr, ZnSe, GaAs, and Ge. Vibrations are found to be an increasing function of ionicity, with the cation sublattice always

Why is EXAFS for complex concentrated alloys so hard? Challenges and opportunities for measuring ordering with X-ray absorption spectroscopy

October 16, 2023
Author(s)
Howie Joress, Bruce D. Ravel, Elaf Anber, Jonathan Hollenbach, Debashish Sur, Mitra Taheri, Brian DeCost
Short-range order (SRO) is a critical driver of properties (e.g., corrosion resistance and tensile strength) in multicomponent alloys such as complex concentrated alloys (CCAs). Extended X-ray absorption fine structure (EXAFS) is a powerful technique well

Structural Origin of Recovered Ferroelectricity in BaTiO3 Nanoparticles

August 24, 2023
Author(s)
Bruce D. Ravel, Trevor Tyson, Han Zhang, Sizhan Liu, SANJIT GHOSE, U.J. Idehenre, Yury Barnakov, S.A. Basun, D.R. Evans
Nanoscale BaTiO3 particles (10 nm) prepared by ball-milling a mixture of oleic acid and heptane have been reported to have an electric polarization several times larger than that for bulk BaTiO3. In this work, detailed local, intermediate, and long-range

Self-driving Multimodal Studies at User Facilities

January 22, 2023
Author(s)
Bruce D. Ravel, Phillip Michael Maffettone, Daniel Allan, Stuart Campbell, Matthew Carbone, Brian DeCost, Howie Joress, Dmitri Gavrilov, Marcus Hanwell, Joshua Lynch, Stuart Wilkins, Jakub Wlodek, Daniel Olds
Multimodal characterization is commonly required for understanding materials. User facilities possess the infrastructure to perform these measurements, albeit in serial over days to months. In this paper, we describe a unified multimodal measurement of a

The Inner Shell Spectroscopy Beamline at NSLS-II: a facility for in situ and operando X-ray absorption spectroscopy for materials research

July 1, 2022
Author(s)
Bruce D. Ravel, Denis Leshchev, Bruno Luvizotto, Ruslan Kadyrov, Klaus Attenkofer, Eli Stavitski
Abstract The Inner Shell Spectroscopy (ISS) beamline on the 8-ID station at the National Synchrotron Light Source II (NSLS-II), Upton, NY, USA, is a high throughput X-ray Absorption Spectroscopy beamline designed for the in situ, operando, and time

Machine learning enabling high-throughput and remote operations at large-scale user facilities

May 18, 2022
Author(s)
Bruce D. Ravel, Tatiana Konstantinova, Phillip Michael Maffettone, Stuart Campbell, Andi Barbour, Daniel Olds
Imaging, scattering, and spectroscopy are fundamental in understanding and discovering new functional materials. Contemporary innovations in automation and experimental techniques have led to these measurements being performed much faster and with higher

A Roadmap for LIMS at NIST Material Measurement Laboratory

April 11, 2022
Author(s)
Gretchen Greene, Jared Ragland, Zachary Trautt, June W. Lau, Raymond Plante, Joshua Taillon, Adam Abel Creuziger, Chandler A. Becker, Joe Bennett, Niksa Blonder, Lisa Borsuk, Carelyn E. Campbell, Adam Friss, Lucas Hale, Michael Halter, Robert Hanisch, Gary R. Hardin, Lyle E. Levine, Samantha Maragh, Sierra Miller, Chris Muzny, Marcus William Newrock, John Perkins, Anne L. Plant, Bruce D. Ravel, David J. Ross, John Henry J. Scott, Christopher Szakal, Alessandro Tona, Peter Vallone
Instrumentation generates data faster and in higher quantity than ever before, and interlaboratory research is in historic demand domestically and internationally to stimulate economic innovation. Strategic mission needs of the NIST Material Measurement

Stoichiometry and Phase Composition of MOCVD Barium Titanate Films

October 12, 2021
Author(s)
Charles E. Bouldin, Joseph Woicik, Bruce Ravel, Debra Kaiser, Mark D. Vaudin
X-ray absorption fine structure (XAFS), x-ray diffraction (XRD) and x-ray fluorescence (XRF) have been used to study the stoichiometry and phase composition of thin (approximately equal to} 1 micron) films deposited on MgO substrates. Deposition

A Synchrotron X-ray Micro-Spectroscopy Study of the Explosive Melt Glass Derived From the Trinity Nuclear Test

April 28, 2019
Author(s)
Bruce D. Ravel, Daniel E. Crean, Daniel J. Bailey, M. C. Stennett, Claire L. Corkhill, Ryan Tappero, N. C. Hyatt
Trinitite, the explosive melt glass derived from the Trinity nuclear test, is of interest as a model material for nuclear forensics investigation. However, there remains uncertainty as to the mechanism of trinitite formation. In this study, new insight is

Non-Resonant Valence-to-Core X-ray Emission Spectroscopy of Niobium

March 23, 2018
Author(s)
Bruce D. Ravel, A. J. Kropf, Dali Yang, Mengen Wang, Mehmet Topsokal, Deyu Lu, M. C. Stennett, N. C. Hyatt
The valence-to-core (V2C) portion of X-ray Emission Spectroscopy (XES) measures the electron 15 states close to the Fermi level. These states are involved in bonding, thus provide a measure of the 16 chemistry of the material. In this manuscript, we show

The effect of self-consistent potentials on EXAFS analysis

November 1, 2017
Author(s)
Bruce D. Ravel, M. Newville, Josh J. Kas, John J. Rehr
We present an EXAFS-oriented theory program based on the popular Feff8 and providing an application programming interface designed to make it easy to integrate high-quality theory into EXAFS analysis software. We then use this new code to examine the

Ultrafast time-resolved x-ray absorption spectroscopy of ferrioxalate photolysis with a laser plasma x-ray source and microcalorimeter array

February 17, 2017
Author(s)
Galen C. O'Neil, Joel N. Ullom, Luis Miaja Avila, Young Il Joe, Joseph W. Fowler, Carl D. Reintsema, Daniel S. Swetz, Kevin L. Silverman, Daniel R. Schmidt, Bruce D. Ravel, Gene C. Hilton, William B. Doriese, Bradley K. Alpert, Ralph Jimenez
Using a table-top apparatus based upon a laser plasma x-ray source and an array of cryogenic microcalorimeter x-ray detectors, we have measured the transient x-ray absorption spectrum during the ferrioxalate photoreduction reaction. We observe the Fe K

XAFS Data Interchange: A single spectrum XAFS data file format

June 9, 2016
Author(s)
Bruce D. Ravel, M. Newville
We propose a standard data format for the interchange of XAFS data. The XAFS Data Interchange (XDI) standard is meant to encapsulate a single spectrum of XAFS along with relevant metadata. XDI is a text-based format with a simple syntax which clearly

Abiotic bromination of soil organic matter

October 15, 2015
Author(s)
Bruce D. Ravel, Alessandra C. Leri
Biogeochemical transformations of plant-derived soil organic matter (SOM) involve complex abiotic and microbially mediated reactions. One such reaction is halogenation, which occurs naturally in the soil environment and has been associated with enzymatic