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Search Publications by: John Vinson (Fed)

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Displaying 1 - 25 of 42

A multi-edge study: investigating Co oxidation states of pristine LiNixMnyCo1-x-yO2 cathode materials by high energy-resolution X-ray spectrometry

March 14, 2024
Author(s)
Karina Bzheumikhova, Claudia Zech, Kai Schuler, John Vinson, Yves Kayser, Burkhard Beckhoff
The investigation of Co oxidation states in pristine LiNixMnyCo1−x−yO2 (NMC) cathodes (NMC111, NMC622, NMC811) has been a subject of ongoing debate, with conflicting findings in the literature. In this study, we present a novel and comprehensive approach

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

Titanium and titanium oxides at the K- and L-edges: comparing theoretical calculations to X-ray absorption and X-ray emission measurements

August 2, 2023
Author(s)
Karina Bzheumikhova, John Vinson, Ranier Unterumsberger, Malte Wansleben, Claudia Zech, Kai Schuler, Yves Kayser, Philipp Honicke, Burkhard Beckhoff
Using well-calibrated experimental data we demonstrate the applicability of theoretical X-ray absorption spectroscopy (XAS) as well as X-ray emission spectroscopy (XES) calculations for titanium (Ti), titanium oxide (TiO), and titanium dioxide (TiO2) at

Lightshow: a Python package for writing computational x-ray absorption spectroscopy input files

July 29, 2023
Author(s)
Matthew Carbone, Fanchen Meng, Christian Vorwerk, Benedikt Mauer, Fabian Peschel, Xiaohui Qu, Eli Stavitski, Claudia Draxl, John Vinson, Deyu Lu
Spectroscopy simulations are a critical tool for the interpretation of experiment, the development of new theoretical understanding, and fast screening of new molecules and materials. Systematically setting up input files for different simulation codes and

Investigating the electronic structure of high explosives with x-ray Raman spectroscopy

November 14, 2022
Author(s)
Oscar Ariel Paredes Mellone, Dimosthenis Sokaras, Trevor Willey, Michael Nielsen, John Vinson
We investigate the sensitivity and potential of a synergistic experiment-theory X-ray Raman spectroscopy (XRS) methodology on revealing and following the static and dynamic electronic structure of high explosive molecular materials. We show that advanced

Near-edge x-ray absorption and emission of cyanates and thiocyanates

September 20, 2022
Author(s)
Karina Bzheumikhova, John Vinson, Yves Kayser, Rainer Unterumsberger, Terrence J. Jach, Burkhard Beckhoff
The comparability and reliability of the analysis of the electronic structure of selected cyanates and thio- cyanates at the nitrogen K edge based on BSE calculations have been investigated in this work. Using high-resolution x-ray spectroscopy with

Advances in the \sc ocean}-3 spectroscopy package

May 18, 2022
Author(s)
John Vinson
The \sc ocean} code for calculating near-edge x-ray spectra using the Bethe-Salpeter equation is briefly reviewed. The code is capable of calculating UV/Vis, near-edge x-ray absorption or non-resonant scattering, and resonant inelastic x-ray scattering

The local structure of sulfur vacancies on the basal plane of monolayer MoS2

April 5, 2022
Author(s)
Angel Garcia-Esparza, Sangwook Park, Abrosham Hadi, John Vinson, Baxter Abraham, Alessandro Gallo, Dennis Nordlund, Taeho Roy Kim, Roberto Alonso-Mori, Jean-Luc Bredas, Xiaolin Zheng, Dimosthenis Sokaras
The nature of the S-vacancy is central to controlling the electronic properties of monolayer MoS2. Understanding the geometric and electronic structures of the S-vacancy on the basal plane of monolayer MoS2 remains elusive. Here, operando S K-edge X-ray

In-situ Stress Measurements During CO Adsorption onto Pt

February 24, 2022
Author(s)
David Raciti, Gery R. Stafford, Kathleen Schwarz, John Vinson
The change in surface stress associated with the adsorption and oxidative stripping of carbon monoxide (CO) on (111)-textured Pt is examined using the wafer curvature method in 0.1 M KHCO3 electrolyte. The curvature of the Pt cantilever electrode was

Elucidating the local atomic and electronic structure of amorphous oxidized superconducting niobium films

December 16, 2021
Author(s)
Thomas Harrelson, Evan Sheridan, Ellis Kennedy, John Vinson, Alpha N'Diaye, M. Altoe, Alex Weber-Bargioni, Adam Schwartzberg, Irfan Siddiqi, D. Ogletree, Mary Scott, Sinead Griffin
Qubits made from superconducting materials are a mature platform for quantum information science application such as quantum computing. However, materials-based losses are now a limiting factor in reaching the coherence times needed for applications. In

Origin of enhanced water oxidation activity in an iridium single atom anchored on NiFe oxyhydroxide catalyst

August 31, 2021
Author(s)
Xueli Zheng, Jing Tang, Allesandro Gallo, Jose A. Garrido Torres, Xiaoyun Yu, Peter Ercius, Haiyan Mao, Emily Been, Constantine J. Athanitis, Sirine C. Fakra, Chengyu Song, Ryan Davis, Jeffrey A. Reimer, John Vinson, Michal Bajdich, Yi Cui
The efficiency of the synthesis of renewable fuels and feedstocks from electrical sources is limited, at present, by the sluggish water oxidation reaction. Single-atom catalysts (SACs) with a controllable coordination environment and exceptional atom

Coulombically-stabilized oxygen hole polarons enable fully reversible oxygen redox

July 1, 2021
Author(s)
Iwnetim I. Abate, Chaitanya D. Pemmaraju, Se-Young Kim, Sami Sainio, Brian Moritz, John Vinson, Michael F. Toney, Wanli Yang, William E. Gent, Thomas P. Devereaux, Linda F. Nazar, William C. Chueh
Stabilizing high-valent redox couples and exotic electronic states necessitates an understanding of the stabilization mechanism. In oxides, whether they are being considered for energy storage or computing, highly oxidized oxide-anion species rehybridize

Database of Ab Initio L-edge X-ray Absorption Near Edge Structure

June 11, 2021
Author(s)
Yiming Chen, Chi Chen, Chen Zheng, Shyam Dwaraknath, Matthew K. Horton, Jordi Cabana, John J. Rehr, John Vinson, Alan K. Dozier, Kristin A. Persson, Shyue P. Ong
The L-edge X-ray Absorption Near Edge Structure (XANES) is widely used in the characterization of transition metal compounds. Here, we report the development of a database of computed L-edge XANES using the multiple scattering theory-based FEFF9 code. The

2p x-ray absorption spectroscopy of 3d transition metal systems

April 3, 2021
Author(s)
Eric L. Shirley, John Vinson, Frank de Groot, Hebatalla Elnaggar, Federica Frati, Ru-pan Wang, Mario Delgado, Michel van Veenendaal, Maurits Haverkort, Robert Green, Yaroslav Kvashnin, Atsushi Hariki, Harry Ramanantoanina, Claude Daul, Bernard Delley, Michael Odelius, Marcus Lundberg, Oliver Kuhn, Sergey Bokarev, Keith Gilmore, Mauro Stener, Giovanni Fronzoni, Piero Decleva, Peter Kruger, Marius Retegan, Javier Fernandez-Rodriguez, Gerritt van der Laan, Yves Joly, Christian Vorwerk, Claudia Draxl, John Rehr, Arata Tanaka, Hidekazu Ikeno
A variety of methods are presented that are presently used to treat x-ray absorption spectra of transition-metal 2p edges in a wide range of compounds. Different methods include different methods of chemical realism versus featuring the simplifications of

The OCEAN Project

March 10, 2021
Author(s)
Eric L. Shirley, John T. Vinson, Keith Gilmore
This chapter presents a high-level description of a suite of programs denoted by the acronym OCEAN (Obtaining Core Excitation spectra ab initio and with NBSE), where NBSE denotes the underlying NIST Bethe-Salpeter Equation program. The main computational

Operando Study of Thermal Oxidation of Monolayer MoS2

March 1, 2021
Author(s)
Sangwook Park, Angel Garcia-Esparza, Hadi Abroshan, Baxter Abraham, John Vinson, Allesandro Gallo, Dennis Nordlund, Joonsuk Park, Taeho R. Kim, Roberto Alonso-Mori, Dimosthenis Sokaras, Xiaolin Zheng
Monolayer MoS2 is a promising semiconductor to overcome the physical dimension limits of the microelectronic devices. Understanding the thermochemical stability of MoS2 is essential since these devices generate heat and are susceptible to oxidative

The anisotropy in the optical constants of quartz crystals for soft X-rays

February 19, 2021
Author(s)
Anna Andrle, Phillipp H?nicke, John Vinson, Richard Quintanilha, Qais Saadeh, Sebastian Heidenreich, Frank Scholze, Victor Soltwisch
The refractive index of a y-cut SiO2 crystal surface is reconstructed from orientation-dependent soft X-ray reflectometry measurements in the energy range from 45 to 620 eV. Owing to the anisotropy of the crystal structure in the (100) and (001) directions

Site-Specific Structure at Multiple Length Scales in Kagome Quantum Spin Liquid Candidates

December 14, 2020
Author(s)
Rebecca W. Smaha, Idris Boukahil, Charles J. Titus, Jack Mingde Jiang, John P. Sheckelton, Wei He, JiaJia Wen, John Vinson, SuYin G. Wang, Yu-Sheng Chen, Simon J. Teat, Thomas P. Devereaux, Chaitanya D. Pemmaraju, Young S. Lee
Realizing a quantum spin liquid (QSL) ground state in a real material is a leading issue in condensed matter physics research. In this pursuit, it is crucial to fully characterize the structure and influence of defects, as these can significantly affect

Restricting Orbital Angular Momentum by Transverse Coherence

September 5, 2020
Author(s)
Ronald L. Cappelletti, John T. Vinson
A traveling wave or wave packet may possess orbital angular momentum in the form of a phase vortex about its axis of propagation. These orbital angular momentum states are a general wave phenomenon, and, as such, can be realized for individual wave packets