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Physics

Spectroscopy

Search Publications

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  • Published Date
Displaying 26 - 50 of 1690

Observation of a promethium complex in solution

May 22, 2024
Author(s)
Bruce D. Ravel, Darren Driscoll, Frankie White, SUBHAMAY PRAMANIK, Jeffrey Einkauf, Dmytro Bykov, Santanu Roy, Richard Mayes, Laetitia Delmau, Samantha Schrell, Thomas Dyke, April Miller, Matt Silveira, Silveira2 van Cleve, Roy Copping, Sandra Davern, Santa Jansone-Popova, Ilja Popovs, Alexander Ivanov
Lanthanide rare earth metals are ubiquitous in modern technologies, but we know little about chemistry of the 61st element, promethium (Pm), a lanthanide which is highly radioactive and inaccessible. Despite its significance, Pm has conspicuously been

Understanding the Origin and Implication of the Indirect-to-Direct Bandgap Transition in Multilayer InSe

May 2, 2024
Author(s)
Nicholas Pike, Ruth Pachter, Michael Altvater, Chris Stevens, Matthew Klein, Joshua Hendrickson, Huairuo Zhang, Sergiy Krylyuk, Albert Davydov, Nicholas Glavin
Indium selenide (InSe) multilayers have attracted much interest recently due to their electronic and optical properties, partially dependent on the existence of an indirect-to-direct bandgap transition that is correlated to the multilayer thickness. In

Nanoscale Three-Dimensional Imaging of Integrated Circuits Using a Scanning Electron Microscope and Transition-Edge Sensor Spectrometer

April 30, 2024
Author(s)
Nathan Nakamura, Paul Szypryt, Amber Dagel, Bradley Alpert, Douglas Bennett, W.Bertrand (Randy) Doriese, Malcolm Durkin, Joseph Fowler, Dylan Fox, Johnathon Gard, Ryan Goodner, James Zachariah Harris, Gene C. Hilton, Edward Jimenez, Burke Kernen, Kurt Larson, Zachary H. Levine, Daniel McArthur, Kelsey Morgan, Galen O'Neil, Christine Pappas, Carl D. Reintsema, Dan Schmidt, Peter Schulz, Daniel Swetz, Kyle Thompson, Joel Ullom, Leila R. Vale, Courtenay Vaughan, Christopher Walker, Joel Weber, Jason Wheeler
X-ray nanotomography is a powerful tool for the characterization of nanoscale materials and structures, but it is difficult to implement due to the competing requirements of X-ray flux and spot size. Due to this constraint, state-of-the-art nanotomography

Instrument Development for Spectroscopic Ellipsometry and Diffractometry in the EUV

April 24, 2024
Author(s)
Stephanie Moffitt, Bryan Barnes, Thomas A. Germer, Steven Grantham, Eric Shirley, Martin Sohn, Daniel Sunday, Charles S. Tarrio
Semiconductor devices are noted for ever-decreasing dimensions but now are also becoming more complex. While scanning probe microscopy can still resolve the smallest features, it does not have the throughput for high-volume characterization of full wafers

Benford's law in atomic spectra and opacity databases

April 21, 2024
Author(s)
Yuri Ralchenko, Jean-Christophe Pain
The intriguing law of anomalous numbers, also named Benford's law, states that the significant digits of data follow a logarithmic distribution favoring the smallest values. In this work, we test the compliance with this law of the atomic databases

Evaluating Models That Predict Epoxy Conversion Using Rheological Properties

April 15, 2024
Author(s)
Stian Romberg, Paul Roberts, Chad R. Snyder, Anthony Kotula
Simultaneous rheology and conversion measurements of neat and composite epoxy resins reveal that conventional models neither accurately nor fully describe the relationship between rheology and conversion. We find that models predicting thermoset conversion

Debye-Waller Effects in Bethe-Salpeter Calculations

March 3, 2024
Author(s)
Eric Shirley, Joseph Woicik
We present a method to incorporate Debye-Waller effects on core-excitation spectra in methods other than real-space multiple scattering formulations. The method draws ideas from multiple-scattering theory to realize effects of variations in interatomic

Zeeman effect in the weak and intermediate field regime of Kr isotopes at the linear plasma device PSI-2

February 16, 2024
Author(s)
Yuri Ralchenko, DIPTI DIPTI, Oleksandr Marchuk, Marc Sackers, Stephan Ertmer, Sebastijan Brezinsek, Arkadi Kreter
Laser absorption spectroscopy provides high-resolution spectra of atomic transitions that reveal many often inaccessible nuances. Correctly analyzing the absorption spectra is impossible without accurately capturing the line shape. We demonstrate in this

Multi-code Benchmark on Ti K-edge X-ray Absorption Spectra of Ti-O Compounds

January 11, 2024
Author(s)
Fanchen Meng, Benedikt Maurer, Fabian Peschel, Sencer Selcuk, Xiaohui Qu, Mark S Hybertsen, Christian Vorwerk, Claudia Draxl, John Vinson, Deyu Lu
X-ray absorption spectroscopy (XAS) is an element-specific materials characterization technique that is sensitive to structural and electronic properties. First-principles simulated XAS has been widely used as a powerful tool to interpret experimental

Tracking Active Phase Behavior on Boron Nitride during the Oxidative Dehydrogenation of Propane Using Operando X-Ray Raman Spectroscopy

November 6, 2023
Author(s)
Melissa Cendejas, Oscar Paredes Mellone, Unni Kurumbail, Zisheng Zhang, Jacob Jansen, Faysal Ibrahim, Son Dong, John Vinson, Anastassia Alexandrova, Dimosthenis Sokaras, Simon Bare, Ive Hermans
Hexagonal boron nitride (hBN) is a highly selective catalyst for the oxidative dehydrogenation of propane (ODHP) to propylene. Using a variety of ex situ characterization techniques, the activity of the catalyst has been attributed to the formation of an

Nanosecond time-resolved dual-comb absorption spectroscopy

October 30, 2023
Author(s)
David Long, Matthew Cich, Carl Mathurin, Garrett Mathews, Adam Heiniger, Augustine Frymire, Gregory Rieker
Frequency combs have revolutionized the field of optical spectroscopy, enabling researchers to probe molecular systems with a multitude of accurate and precise optical frequencies. Although there have been tremendous strides in direct frequency comb

Single-Detector Double-Beam Modulation for High-Sensitivity Infrared Spectroscopy

October 25, 2023
Author(s)
Seongmin Kim, Yow-Ren Chang, Young Jong Lee
Balanced detection based on double beams is widely used to reduce common-mode noises, such as laser intensity fluctuation and irregular wavelength scanning, in absorption spectroscopy. However, employing an additional detector can increase the total system

Next-Generation Chip-Scale Atomic Clocks

October 16, 2023
Author(s)
John Kitching, Matthew Hummon, William McGehee, Ying-Ju Wang, Susan Schima
We describe work toward the development of next-generation chip-scale atomic clocks, which combine small size, low power consumption and manufacturability with high frequency stability. The use of optical transitions in microfabricated vapor cells improves

Strain-activated stimulated emission from multilayer MoSe2 in a narrow operation window

September 24, 2023
Author(s)
Yuankun Lin, Noah Hurley, Steve Kamau, Evan Hathaway, Yan Jiang, Roberto Gonzalez Rodriguez, Sinto Varghese, Sergiy Krylyuk, Albert Davydov, Yuanxi Wang, Anupama Kaul, Jingbiao Cui
Herein, photoluminescence (PL) and fluorescence lifetime imaging (FLIM) in multilayer MoSe2 are studied. Strain-activated stimulated emission via defect levels in multilayer MoSe2 under laser excitation is observed, for the first time in defects of

Open-path measurement of stable water isotopologues using mid-infrared dual-comb spectroscopy

September 8, 2023
Author(s)
Daniel Herman, Griffin Mead, Fabrizio Giorgetta, Esther Baumann, Nathan Malarich, Brian Washburn, Nathan R. Newbury, Ian Coddington, Kevin Cossel
We present an open-path mid-infrared dual-comb spectrometer (DCS) capable of precise measurement of the stable water isotopologues H216O and HD16O. This system runs in a remote configuration at a rural test site with high uptime and achieves a precision of

Radiative Decay Rate and Branching Fractions of MgF

September 8, 2023
Author(s)
Eric Norrgard, Catherine Cooksey, Stephen Eckel, Nickolas Pilgram, Kayla Rodriguez, Howard W. Yoon, Yuly Andrea Chamorro Mena, Lukas Pasteka, Anastasia Borschevsky
Here we report measured and calculated values of radiative decay rates and vibrational branching fractions for the A$^2\Pi$ state of MgF. The decay rate measurements use time-correlated single photon counting with roughly 1\,\% total uncertainty. Branching

Dual-Comb Spectroscopy of Carbon Dioxide and Methane Across a 14.5 km Long Outdoor Path

September 1, 2023
Author(s)
Fabrizio Giorgetta, Esther Baumann, Brian Washburn, Nathan Malarich, Jean-Daniel Deschenes, Ian Coddington, Nathan Newbury, Kevin Cossel
Greenhouse-gas dual-comb spectroscopy is extended to a city-scale 14.5-km path length using remote receiver and data acquisition. This configuration enables lower link losses and longer path lengths compared to folded paths with a remote retroreflector

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

Observations and identifications of extreme ultraviolet spectra of Ca-like to Na-like neodymium ions using an electron beam ion trap

August 23, 2023
Author(s)
Yang Yang, Dipti Dipti, Chihiro Suzukic, A. C. Gall, R. Silwal, Samuel Sanders, Joseph N. Tan, Aung S. Naing, Endre Takacs, Yuri Ralchenko
Extreme ultraviolet (EUV) radiation from M-shell Ca-like, Nd40+, through Nalike, Nd49+, highly charged ions have been measured at an electron beam ion trap (EBIT) facility at the National Institute of Standards and Technology. To produce the ionization