Article
Multidisciplinary Sciences
Manuel Cordova, Pinelopi Moutzouri, Sten O. Nilsson Lill, Alexander Cousen, Martin Kearns, Stefan T. Norberg, Anna Svensk Ankarberg, James Mccabe, Arthur C. Pinon, Staffan Schantz, Lyndon Emsley
Summary: In this study, the atomic-level ensemble structure of the amorphous form of the drug AZD4625 was determined by combining solid-state NMR experiments with molecular dynamics simulations and machine-learned chemical shifts. Preferred conformations and intermolecular interactions in the amorphous sample were analyzed to understand the stabilization of the amorphous form of the drug.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Condensed Matter
K. Itoh, R. Yamada, J. Saida, K. Ikeda, T. Otomo
Summary: By investigating the structure of Cu67Zr33 amorphous alloy, it was found that there are tetrahedral and octahedral holes as well as other larger holes in the alloy, and the distribution of free volumes for these holes can be described by an exponential function. Furthermore, local structural fluctuations due to densely and loosely packed tetrahedral holes lead to negative free volume spaces.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Chemistry, Multidisciplinary
Yu-Tian Zhang, Yun-Peng Wang, Xianli Zhang, Yu-Yang Zhang, Shixuan Du, Sokrates T. Pantelides
Summary: This paper addresses the question of the structure of single-atom-thick amorphous monolayers, and finds that the structure of elemental amorphous graphene and binary monolayer amorphous BN is different from previously debated options. The implications for other nonelemental 2D and bulk amorphous materials are also discussed.
Article
Chemistry, Multidisciplinary
Alberto Garcia-Fernandez, Sebastian Svanstrom, Cody M. Sterling, Abhijeet Gangan, Axel Erbing, Chinnathambi Kamal, Tamara Sloboda, Birgit Kammlander, Gabriel J. Man, Hakan Rensmo, Michael Odelius, Ute B. Cappel
Summary: This study investigates the surface properties and electronic structure of lead halide perovskite single crystals using synchrotron-based soft X-ray photoelectron spectroscopy, molecular dynamics simulations, and density functional theory. The results provide reference spectra for photoelectron spectroscopy investigations of polycrystalline thin films and can be used to optimize the design of device interfaces.
Article
Multidisciplinary Sciences
J. Niskanen, A. Vladyka, J. Niemi, C. J. Sahle
Summary: In this study, we explore the sensitivity of several core-level spectroscopic methods to the atomistic structure using water molecule as a test system. We define a metric to measure the magnitude of spectral change as a function of structure, which enables us to identify structural regions with high spectral sensitivity. By employing machine-learning emulator-based decomposition of structural parameter space, we are able to recover more spectral variance and identify spectroscopically dominant degrees of freedom.
ROYAL SOCIETY OPEN SCIENCE
(2022)
Article
Chemistry, Physical
Ana Cotai, Bogdan Viorel Neamtu, Florin Popa, Traian Florin Marinca, Olivier Isnard, Ionel Chicinas
Summary: This study compares HITPERM type alloys prepared by wet and dry mechanical alloying, finding that amorphization occurred after 40 hours of milling in wet conditions, but not after 100 hours in dry conditions. Various analyses were performed to investigate the thermal stability and crystallization kinetics of the amorphous powders.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
K. Itoh, J. Saida, E. R. Barney, A. C. Hannon
Summary: The occupation of interatomic hole sites by deuterium in a deuterated Ni67Zr33 amorphous alloy was investigated using diffraction measurements and simulation techniques. The results show that deuterium atoms occupy various types of polyhedral hole sites, as well as tetrahedral ones. The occupation of different hole sites has different effects on the volume of the material.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Iskander Mukatayev, Florient Moevus, Benoit Sklenard, Valerio Olevano, Jing Li
Summary: X-ray photoemission spectroscopy (XPS) directly provides information on atomic composition and stoichiometry by measuring core-electron binding energies. The chemical shift, obtained from the shift in binding energy, reveals the precise chemical type of bonds and provides additional information on the local structure. The major contributor to the chemical shift is identified to be classical electrostatics, one order of magnitude larger than the correlation, through a theoretical study comparing different theories.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Iskander Mukatayev, Florient Moevus, Benoit Sklenard, Valerio Olevano, Jing Li
Summary: X-ray photoemission spectroscopy (XPS) provides direct information on atomic composition and stoichiometry, as well as the precise chemical type of bonds through the chemical shift. In this study, different theoretical approaches are compared to assess their accuracy in predicting the carbon 1s chemical shift. Classical electrostatics is identified as the major contributor to the chemical shift, surpassing the correlation by one order of magnitude.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Robert Streubel, D. Simca Bouma, Frank Bruni, Xiaoqian Chen, Peter Ercius, Jim Ciston, Alpha T. N'Diaye, Sujoy Roy, Steve D. Kevan, Peter Fischer, Frances Hellman
Summary: Experimental evidence of 3D chiral spin textures, including helical spins and skyrmions with different chirality and topological charge, has been reported in amorphous Fe-Ge thick films. These results demonstrate that structurally and chemically disordered materials can resemble inversion symmetry broken systems with similar magnetic properties, moments, and states, providing greater flexibility in materials synthesis, voltage, and strain manipulation.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Physical
Jaroslav Zenisek, Pavel Ondracka, Jan Cencnal, Pavel Soucek, David Holec, Petr Vasina
Summary: This paper critically evaluates the applicability of a procedure proposed by Mirzaei et al. (Surf. Coat. Technol. 358, 2019) for fitting the XPS spectrum of amorphous W-B-C material. The authors show that W-W bonds significantly influence the positions of peak components, which has implications for the correct interpretation of measured XPS spectra. Their analysis confirms expected chemical shifts caused by W-B and W-C bonds and reveals the same directional shift of W-W bonds and W-B bonds in the W 4f electronic states.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Seyong Choi, Dipak Patel, Jung Ho Kim, Hiroaki Kumakura, Akiyoshi Matsumoto, Gen Nishijima, Su-Hun Kim, Jinho Joo, Minoru Maeda
Summary: The evaluation and control of amorphous phases in materials are crucial in optimizing their properties. This study focuses on the effects of residual amorphous impurities on the superconducting performance of polycrystalline MgB2 materials prepared with hydrocarbon doping. Carbon doping is effective for enhancing the transport critical current, and different doping methods significantly impact the formation of MgB2 phase and subsequent superconducting properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Review
Chemistry, Physical
Luca Bignardi, Paolo Lacovig, Rosanna Larciprete, Dario Alfe, Silvano Lizzit, Alessandro Baraldi
Summary: The interest in understanding and controlling the properties of two-dimensional materials (2DMs) has led to significant research efforts involving condensed matter physics and materials science. Surface-science based techniques, particularly synchrotron-based X-ray photoelectron spectroscopy (XPS), have been essential in elucidating many aspects of 2DMs properties and growth mechanisms. This review showcases relevant examples of studies where XPS and other techniques were crucial in unraveling the synthesis and properties of 2DMs at surfaces.
SURFACE SCIENCE REPORTS
(2023)
Article
Multidisciplinary Sciences
Jennifer Donohue, Steven E. Zeltmann, Karen C. Bustillo, Benjamin Savitzky, Mary Ann Jones, Gregory F. Meyers, Colin Ophus, Andrew M. Minor
Summary: Understanding and visualizing the heterogeneous structure of immiscible semicrystalline polymer systems is crucial for optimizing their morphology and microstructure. In this study, a cryogenic 4D-STEM technique was used to map the distribution of both crystalline and amorphous phases in an iPP/EO multilayer film. The resulting map revealed a sharp interface between the amorphous iPP and EO, indicating their incompatibility and immiscibility.
Article
Physics, Multidisciplinary
T. P. H. Sidiropoulos, N. Di Palo, D. E. Rivas, S. Severino, M. Reduzzi, B. Nandy, B. Bauerhenne, S. Krylow, T. Vasileiadis, T. Danz, P. Elliott, S. Sharma, K. Dewhurst, C. Ropers, Y. Joly, K. M. E. Garcia, M. Wolf, R. Ernstorfer, J. Biegert
Summary: The detection of energy conversion pathways between photons, charge carriers, and the lattice is crucial for understanding fundamental physics and advancing materials and devices. Attosecond core-level x-ray absorption fine-structure spectroscopy (XANES) provides a clear and simultaneous view of the temporal evolution of the photon-carrier-phonon system, revealing surprising new results. By applying this method to graphite, complex mechanisms involving electrons, holes, and optical phonons were elucidated, showcasing the utility of core-level XANES with attosecond temporal resolution for studying energy flow inside materials.
Article
Chemistry, Physical
Xiaoqing Li, Daixiu Wei, Levente Vitos, Raquel Lizarraga
JOURNAL OF ALLOYS AND COMPOUNDS
(2020)
Article
Chemistry, Physical
Paolo Giannozzi, Oscar Baseggio, Pietro Bonfa, Davide Brunato, Roberto Car, Ivan Carnimeo, Carlo Cavazzoni, Stefano de Gironcoli, Pietro Delugas, Fabrizio Ferrari Ruffino, Andrea Ferretti, Nicola Marzari, Iurii Timrov, Andrea Urru, Stefano Baroni
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Physics, Condensed Matter
Juan Alberto Rios-Gonzalez, Eduardo Menendez-Proupin, Juan Luis Pena
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2020)
Article
Nanoscience & Nanotechnology
Jesus E. Castellanos-Aguila, Lucas Lodeiro, Eduardo Menendez-Proupin, Ana L. Montero-Alejo, Pablo Palacios, Jose C. Conesa, Perla Wahnon
ACS APPLIED MATERIALS & INTERFACES
(2020)
Article
Biochemistry & Molecular Biology
Giovanni La Penna, Davide Tiana, Paolo Giannozzi
Summary: The study presents a method to quickly compute delocalization indices for all atomic pairs while maintaining the same wave function representation as compute-intensive DFT calculations. By integrating this method into Quantum ESPRESSO, a description of covalent bonds can be recovered from the wave function representation.
Article
Materials Science, Multidisciplinary
Li-Yun Tian, Levente Vitos, Raquel Lizarraga
Summary: This study investigates the thermal effects on the elastic and thermodynamic properties of Al-Li and Al-Cr alloys using density-functional theory, finding that higher temperatures lower the modulus values while the addition of Li or Cr increases the Young's modulus. In the case of Al-Cr alloys, the Young's modulus increases linearly with higher Cr concentrations.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Physics, Applied
Raquel Lizarraga, Xiaojie Li, Daixiu Wei, Levente Vitos, Xiaoqing Li
Summary: Quantum mechanics modeling was used to investigate the effects of Ge and Si solute elements on the elastic properties and plastic deformation modes in high-entropy and medium-entropy alloys. The study revealed that the activated deformation modes in all alloys studied are the stacking fault mode (dominant) and the full-slip mode (secondary), with twining becoming favored as the concentrations of Ge and Si increase. The calculated trends for Young's and shear modulus as well as lattice parameters were verified by measurements.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Young Won Choi, C. Moyses Araujo, Raquel Lizarraga
Summary: New superionic conducting glasses have potential as solid electrolytes for all-solid-state Li-ion batteries, but their structure and electrochemical stability need further research. This study investigates the structural and electronic properties of Li3ClO glass and demonstrates that substoichiometric glass can improve the electrochemical stability.
JOURNAL OF POWER SOURCES
(2022)
Article
Chemistry, Physical
Youngwon Choi, Zhihua Dong, Wei Li, Raquel Lizarraga, Se-Kyun Kwon, Levente Vitos
Summary: This study investigates the equilibrium properties of paramagnetic hcp Fe using DFT modeling in combination with alloy theory. The theoretical results are consistent with experimental values when magnetic disorder is properly accounted for, and the longitudinal spin fluctuation effects further improve the theoretical description.
Article
Chemistry, Physical
Bing Tan, Abdul M. Reyes, Eduardo Menendez-Proupin, Sebastian E. Reyes-Lillo, Yanbo Li, Zemin Zhang
Summary: This study demonstrates that by building a gradient homojunction in BiFeO3 photocathodes, a full-space electric field can be induced, resulting in improved photocurrent and H2O2 production. The presence of Bi vacancies significantly modulates the Fermi level of BiFeO3, promoting charge collection.
ACS ENERGY LETTERS
(2022)
Article
Chemistry, Physical
Ana L. Montero-Alejo, Felipe Barria-Caceres, Lucas Lodeiro, Eduardo Menendez-Proupin
Summary: In this study, density functional theory calculations were used to investigate the influence of fullerene derivatives as an electron transport layer in inverted hybrid perovskite solar cells. It was found that only the perovskite surface terminated in a layer rich in methylammonium iodide provides electron transport without energy barriers for fullerene derivatives, while the lead iodide (PbI2)-terminated surface is not passivated with fullerene derivatives. The surface state disappears if the PbI2-terminated surface is treated with ammonium salts or zwitterionic compounds. Thus, the optimal design of perovskite solar cells should consider the barrier-free electron transport between interfaces.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Eduardo Menendez-Proupin, Shivani Grover, Ana L. Montero-Alejo, Scott D. Midgley, Keith T. Butler, Ricardo Grau-Crespo
Summary: This study presents an ab initio molecular dynamics investigation on the (FAPbI(3))(0.875)(MAPbBr(3))(0.125) perovskite, analyzing its structural, thermodynamic, and electronic properties. It is found that the rotation of organic cations is more hindered in the mixed structure, but the mixed perovskite is thermodynamically stable despite the large configurational entropy.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Materials Science, Multidisciplinary
C. Trallero-Giner, E. Menendez-Proupin, E. Suarez Morell, R. Perez-Alvarez, Dario G. Santiago-Perez
Summary: The study focuses on the optical vibrations of monolayer TMDs, developing a generalized continuum approach and analyzing two-dimensional phonon dispersion curves. Model parameters are fitted from density functional perturbation theory calculations, providing an effective tool to describe the phonon dispersion curves of TMD monolayers. Additionally, the evaluation of intravalley Pekar-Frohlich and A(1)-homopolar mode deformation potential coupling mechanisms is carried out to study the effects of metal ions and chalcogen atoms on polaron mass and binding energy. Both mechanisms are argued to be necessary for a correct analysis of polaron properties and processes involving electron-phonon interaction.
Article
Materials Science, Multidisciplinary
M. G. Pala, I. P. Giannozzi, D. Esseni
Article
Chemistry, Multidisciplinary
Mohammadreza Hosseini, Danny E. P. Vanpoucke, Paolo Giannozzi, Masoud Berahman, Nasser Hadipour
