Article
Materials Science, Multidisciplinary
Yulia Mishchenko, Kyle D. Johnson, Janne Wallenius, Denise Adorno Lopes
Summary: In this study, composite UN-AlN, UN-Cr, UN-CrN, and UN-AlN-CrN pellets were fabricated, obtaining an advanced microstructure with different modes of interaction between phases. The results allowed for the assessment of a methodology for fabricating UN composites with controlled microstructure, including the observation of the ternary U2CrN3 phase in pellets containing Cr and CrN dopants.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Chemistry, Physical
Y. O. Yayak, Y. Sozen, F. Tan, D. Gungen, Q. Gao, J. Kang, M. Yagmurcukardes, H. Sahin
Summary: The study shows that single-layer Ge3N4 has a dynamically stable buckled structure with large hexagonal holes, distinct vibrational features, and an indirect band gap semiconductor nature. It can also form type-II vertical heterostructures with various 2D materials and exhibit changes in energy band gap under applied external strain.
APPLIED SURFACE SCIENCE
(2022)
Article
Engineering, Electrical & Electronic
Abdul Majid, Bazgha Khadim, Mohammad Alkhedher, Sajjad Haider, Muhammad Saeed Akhtar
Summary: This work utilizes first-principles investigations and density functional theory (DFT) to design inert gas sensors. Pd cluster-decorated graphene sensors are found to be more reactive and have better sensitivity towards inert gases compared to bare graphene sensors. The findings of this study are important for the fabrication of inert gas sensors.
IEEE SENSORS JOURNAL
(2023)
Article
Materials Science, Multidisciplinary
Cole Moczygemba, Jonathan George, Eduardo Montoya, Eunja Kim, Geronimo Robles, Elizabeth Sooby
Summary: The research and development of high uranium density fuels is crucial for enhancing reactor technology, safety, performance, and economics. This study explores the performance of U3Si2 fuel alloyed with Zr in high temperature steam oxidation environments, demonstrating delayed onset of oxidation and improved homogeneity.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Chemistry, Physical
Juan. M. M. Florez, Miguel. A. A. Solis, Emilio. A. Cortes A. Estay, E. Suarez Morell, Caroline. A. A. Ross
Summary: By investigating the effects of different oxygen vacancy states on the magnetization of SrTi1-xFexO3-δ, our study provides insights into the relationship between vacancy concentration and the oxygen pressure required to maximize the magnetization.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Ahmed O. Elnabawy, Jeffrey A. Herron, Sara Karraker, Manos Mavrikakis
Summary: This study investigates the trends and mechanisms of ammonia electro-oxidation on the (100) facet of eight fcc transition metals, revealing Pt(100) as reactive for N* and facilitating dimerization to N-2 at high potentials. Analysis of structure sensitivity on other metals is also conducted, with general principles proposed for catalyst design in this reaction.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Analytical
Biswanath Mukherjee
Summary: The study utilized DFT computations to investigate a series of transition metal-TCNQ monolayers for bi-functional single atom electrocatalyst towards ORR and OER, revealing that Co-TCNQ monolayer exhibited the best bi-functional catalytic activity. The excess potential of 0.6 V at equilibrium potential was required for OER activity, while an onset potential of 0.34 V was measured for ORR to proceed in acidic media.
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Physical
Caroline Pereira dos Santos, Willian Oliveira Santos, Jocelia Silva Machado Rodrigues, Fernanda Carla Lima Ferreira, Divanizia do Nascimento Souza, Erico Raimundo Pereira de Novais, Glaura Caroena Azevedo de Oliveira, Andrea de Lima Ferreira Novais, Aldimar Machado Rodrigues
Summary: The atomic and electronic properties of amorphous Pb3(PO4)2 and Pb2(PO4)2: Nd3+ were studied using first-principles calculations based on density functional theory. The absence of a band gap in Nd-doped structure indicates the covalent character of the PbPO bond. The presence of impurity Nd3+ does not distort the atomic structure of Pb3(PO4)2, and structures with zero or very narrow gaps have applications in various fields.
COMPUTATIONAL AND THEORETICAL CHEMISTRY
(2022)
Article
Engineering, Chemical
JiaZhen Li, Yue Meng, Zhiyan Gao, Bo Xie, Shengjie Xia, Zhisheng Fu
Summary: In this paper, the stability, adsorption configuration, and activated electronic properties of CO2 on different surfaces (C2N, M/C2N, M2/C2N) were investigated using DFT. The results showed that NiCo/C2N exhibited the highest stability and good CO2 adsorption properties. Additionally, the study explored the generation of C1 products from CO2 reduction and C-C coupling reactions on M/C2N and M2/C2N materials. It was found that the outermost electron distribution and density of states of the transition metals influenced the pathways for C1 generation from CO2 reduction on different surfaces, and NiCo/C2N was favorable for CO2 reduction reactions.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Chemistry, Physical
Nafiseh Mohammadi-rad, Mehdi D. Esrafili, Jaber Jahanbin Sardroodi
Summary: In this study, Fe-doped porous BN nanosheet is proposed as an efficient and noble-metal free electrocatalyst for the oxygen reduction reaction (ORR) process in fuel cells. The ORR process on this electrocatalyst prefers a direct four-electron route.
APPLIED SURFACE SCIENCE
(2022)
Article
Physics, Multidisciplinary
Rui-Qi Wang, Tian-Min Lei, Yue-Wen Fang
Summary: The rapid interest in low-dimensional materials is due to the need for nanoscale solid-state devices with unique properties. Complex transition metal oxide interface holds promise for electronic and spintronics devices. This study shows metal-insulator and ferromagnetic-antiferromagnetic transitions in monolayer MnO2 sandwiched into SrTiO3-based heterointerface systems through interface engineering. First-principles calculations show that metal-insulator and magnetic transitions in the monolayer MnO2 are independent of capping layer thickness. Monolayer MnO2 exhibits 100% spin-polarized two-dimensional electron gases and robust room temperature magnetism, making it a potential candidate for nanoscale spintronics applications.
Article
Materials Science, Multidisciplinary
A. Sengupta
Summary: In this work, novel two-dimensional Janus Ni dichalcogenide materials were proposed and their feasibility, stability, electronic and optical properties were evaluated using ab-initio calculations. NiSSe, among the three materials proposed, exhibited the best energetic and dynamical stability with a metallic bandstructure dominated by the Ni-Se interaction. The optica properties of 2D NiSSe showed a broad spectrum optical response in the infrared, visible, and ultraviolet range.
COMPUTATIONAL MATERIALS SCIENCE
(2022)
Article
Biochemistry & Molecular Biology
Eric Osei-Agyemang, Jean-Francois Paul, Romain Lucas, Sylvie Foucaud, Sylvain Cristol, Anne-Sophie Mamede, Nicolas Nuns, Ahmed Addad
Summary: The mechanical and physical properties of zirconium carbide (ZrC) are limited by its deterioration in oxidizing environments. However, it has a wide range of applications in nuclear reactor lines and nozzle flaps in the aerospace industry. To develop mechanically strong and oxygen-resistant ZrC materials, studying and characterizing the oxidized layers, particularly the interfacial structure between ZrC and the oxidized phases, is crucial.
Article
Materials Science, Multidisciplinary
D. A. Andersson, C. Matthews, Y. Zhang, B. Beeler
Summary: DFT calculations were used to study the thermodynamic and kinetic properties of point defects in the ,B phase of uranium. The fastest diffusion rate was determined to be through a vacancy mechanism in the z crystallographic direction, with good agreement between predicted uranium self diffusivity and experimental data. The study provides valuable information for fuel performance models regarding swelling and gas evolution.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Chemistry, Physical
Theo Cavignac, Stephane Jobic, Camille Latouche
Summary: In this study, a methodology based on constrained density functional theory and vibrational mode computations is presented to simulate and interpret the luminescence spectra of periodic solids. By combining electronic and vibrational contributions, an overall vibrationally resolved emission spectrum is accurately reproduced for Ti-doped BaZrO3, allowing for an unambiguous assignment of the observed luminescence to a Ti3+ + O- -> Ti4+ + O2- charge transfer.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Materials Science, Multidisciplinary
Blas P. Uberuaga, Pauline Simonnin, Kevin M. Rosso, Daniel K. Schreiber, Mark Asta
Summary: This work examines the effect of Cr alloying on mass transport along grain boundaries in Ni. It is found that Cr tends to reduce the rate of mass transport in general, but can greatly enhance atomic mobility in special scenarios. The presence of Cr eliminates grain boundary mobility that is sometimes observed in pure Ni boundaries. These insights provide a better understanding of the role of grain boundary alloying on transport and can contribute to the development of predictive models for materials evolution.
JOURNAL OF MATERIALS SCIENCE
(2022)
Review
Materials Science, Multidisciplinary
Dane Morgan, Ghanshyam Pilania, Adrien Couet, Blas P. Uberuaga, Cheng Sun, Ju Li
Summary: This article explores the application of machine learning in nuclear materials research, particularly in complex time-dependent interactions. Through high-throughput computational and experimental data approaches, machine learning can assist researchers in developing models and making predictions, thereby improving the accuracy and efficiency of research.
CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Christopher N. Singh, Blas Pedro Uberuaga, Stephen J. Tobin, Xiang-Yang Liu
Summary: The relative rate of optical to thermal carrier decay is crucial for optoelectronic device performance, and radiation-induced point defects have a significant impact on this ratio. By employing a first-principles-based theory of multi-phonon emission, the thermal decay rates of six possible point defects in GaAs, a classical optoelectronic material, are evaluated. These rates reveal the propensity of electrons or holes to interact with specific defect vibrations, shedding light on the most detrimental material defects.
Article
Chemistry, Physical
Peter Hatton, Blas Pedro Uberuaga
Summary: In this study, it is found that highly disordered spinels with high concentration of antisite cation pairs still exhibit some short range order in the form of antisite chains. The formation of these chains depends on the chemistry of spinels. The effect of antisite chains on cation vacancy diffusivity varies depending on the spinel chemistry.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Materials Science, Multidisciplinary
Sylvia Koerfer, Alexander Bonkowski, Joe Kler, Peter Hatton, Blas Pedro Uberuaga, Roger A. De Souza
Summary: In this study, cation diffusion in fluorite-structured CeO2 is investigated using classical molecular dynamics and metadynamics simulations. It is found that cation diffusion primarily occurs through cation divacancies, rather than isolated vacancies or cation vacancy-oxygen vacancy associates.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Physics, Applied
R. Auguste, M. O. Liedke, M. Butterling, B. P. Uberuaga, F. A. Selim, A. Wagner, P. Hosemann
Summary: Radiation-induced property changes in materials are caused by energy transfer from incoming particles to the lattice, leading to atom displacement and the formation of extended defects. The extent of these defects depends on dose rate, material, and temperature. This study provides direct experimental evidence of non-equilibrium vacancy formation in silicon through in situ positron annihilation spectroscopy.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Coatings & Films
Sofia K. Pinzon, James A. Valdez, Vancho Kocevski, J. K. Baldwin, Blas P. Uberuaga, Cortney R. Kreller, Benjamin K. Derby
Summary: The study analyzes the effect of different substrate temperatures and altering the oxide cation on the structural and morphological properties of lanthanide sesquioxide thin films. It was found that the structure and morphology of the films can be controlled by manipulating deposition parameters.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Materials Science, Multidisciplinary
Christopher N. Singh, Xiang-Yang Liu, Blas Pedro Uberuaga, Stephen J. Tobin
Summary: There is growing demand for radiation-tolerant optical systems in space and nuclear applications. This study utilizes advanced modeling techniques to design radiation-hard optical materials. Molecular dynamics, density functional theory, and Maxwell's equations were used to analyze the effects of point-defects on radiation-induced attenuation in wet fused silica. Evidence is provided that non-bridging oxygen-hole centers (NBOHC) are the primary cause of attenuation in γ-irradiated optical fibers. The study also highlights the importance of spin-orbit coupling in defining the optical properties of gamma-ray induced defects.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Amitava Banerjee, Edward F. Holby, Aaron A. Kohnert, Shivani Srivastava, Mark Asta, Blas P. Uberuaga
Summary: This study investigates the thermodynamics and kinetics of point defects in hematite (α-Fe2O3) using density functional theory. The calculations reveal that migration barriers for point defects can vary significantly with charge state, especially for cation interstitials. Multiple possible migration pathways are found, attributed to the low symmetry of the corundum crystal structure. Additionally, the anisotropy of long-range diffusion favors diffusion along the c-axis of the crystal.
ELECTRONIC STRUCTURE
(2023)
Article
Materials Science, Multidisciplinary
Anjana Talapatra, Blas Pedro Uberuaga, Christopher Richard Stanek, Ghanshyam Pilania
Summary: The compositional and structural variety of oxide perovskites allows for a wide range of applications. Machine learning models are used to predict the band gap of perovskite compounds and identify stable and synthesizable compounds with desired band gaps.
COMMUNICATIONS MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
V. Kocevski, J. A. Valdez, B. K. Derby, Y. Q. Wang, G. Pilania, B. P. Uberuaga
Summary: Introduces the importance of metastable forms of matter in our everyday lives, and explains that synthesizing these forms is more of an art than a science. Calculates metastable phase diagrams and extracts the metastability threshold to aid in their fabrication. Uses lanthanide sesquioxides (Ln(2)O(3)) as a case study to demonstrate the insight provided by metastable phase diagrams and predict the sequence of metastable phases induced by irradiation in Lu2O3.
MATERIALS ADVANCES
(2023)
Article
Materials Science, Multidisciplinary
David A. Andersson, Christopher R. Stanek, Christopher Matthews, Blas P. Uberuaga
Summary: This article introduces the motivation of new reactor concepts in studying various types of nuclear fuels. It discusses the types, properties, and historical context of the most prevalent nuclear fuels, as well as provides a perspective on the future development of nuclear fuel research. The author believes that the integration of modeling and simulation with experiments will be crucial in extracting the maximum amount of energy from existing fuels in a safe and economical way.
Article
Chemistry, Physical
Vancho Kocevski, Ghanshyam Pilania, Blas P. Uberuaga
Summary: Complex oxides exhibit great functionality due to their varied chemistry and structures. This study introduces a simple metric that correlates the propensity for cation disordering in perovskites, pyrochlores, and spinels with the energy to invert the cation structure. The metric provides a fast and robust way to determine the ease or difficulty of cation disordering, enabling quick screening of compounds for cation-ordering-dependent functionalities.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Peter Hatton, Matthew Hatton, Danny Perez, Blas Pedro Uberuaga
Summary: Accelerated Molecular Dynamics (AMD) is used to study complex systems under realistic conditions and avoid over-driving the system. The growth mechanisms and bubble structures of He bubbles grown under realistic conditions are different from those grown at conventional rates. Caution must be taken when simulating driven systems like this.
MRS COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
R. Auguste, H. L. Chan, E. Romanovskaia, J. Qiu, R. Schoell, M. O. Liedke, M. Butterling, E. Hirschmann, A. G. Attallah, A. Wagner, F. A. Selim, D. Kaoumi, B. P. Uberuaga, P. Hosemann, J. R. Scully
Summary: This study investigated the oxidation process of chromium in air at 700°C, focusing on the behavior and transport of point defects during oxide layer growth. Various characterization techniques were used to analyze the microstructure and chemical composition of chromium oxide. The results showed that the oxide thickness increased with longer oxidation times, and voids formed at the metal/oxide interface in the thicker oxides. The vacancy-type defects decreased overall with longer oxidation times, and the thicker oxide had a lower charge carrier density. These findings suggest that anion oxygen interstitials and chromium vacancy cluster complexes play a role in the transport mechanism in an oxidizing environment at this temperature, providing valuable insights into corrosion regulation.
NPJ MATERIALS DEGRADATION
(2022)
