Review
Materials Science, Multidisciplinary
Serge Maillard, David Andersson, Michel Freyss, Fabien Bruneval
Summary: This paper reviews the role of atomistic techniques in building defect models in crystals and their effectiveness in reproducing important experimental data. Using non-stoichiometric uranium dioxide as an example, eleven point-defect models from the literature are compared and significant differences in defect formation energies and entropies are found. Atomistic-based models face difficulties in predicting the oxygen potential and OM ratio, which may arise from erroneous calculations of the oxygen molecule energy and the energy of oxygen incorporation in UO2, as well as a poor evaluation of the electron-hole formation Gibbs energy.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Chemistry, Physical
Hankun Xu, Kun Lin, Wenjie Li, Qiang Li, Joerg C. Neuefeind, Jue Liu, Kenichi Kato, Jun Miao, Xianran Xing
Summary: In this study, the role of non-stoichiometry in second harmonic generation (SHG) in LiNbO3 was investigated by preparing non-stoichiometric LiNbO3 samples with different Li mole percentages. It was found that reducing the Li content to 47 mol% significantly weakened the SHG response by 50% without affecting the band gap. This effect was attributed to the introduction of anti-occupied Nb and Li vacancies, which reduced local distortions and polarizations of the octahedra, resulting in the decline of SHG response. These findings provide insights for the future design of functional materials with non-stoichiometric compositions.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
Megha Sanjeev, Mark R. Gilbert, Samuel T. Murphy
Summary: This study investigates the influence of stoichiometry deviations on the thermal conductivity of Li2TiO3 through molecular dynamics simulations. The results show that the impact of stoichiometry deviations on thermal conductivity is limited, especially at higher temperatures.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Physics, Applied
Ping Wang, Jun-Liang Chen, Qi Zhou, Yun Tiao Liao, Ying Peng, Ji Sheng Liang, Lei Miao
Summary: In this study, Ag2Se1+x samples were rapidly synthesized by the melting method via changing the ratio of Ag and Se. The carrier concentration and mobility of Ag2Se are optimized by adding excess Se, resulting in high Seebeck coefficient, large power factor, and the maximum figure of merit (ZT).
APPLIED PHYSICS LETTERS
(2022)
Article
Instruments & Instrumentation
S. Xu, G. Noguere, L. Desgranges, J. I. Marquez Damian
Summary: This article focuses on the relationship between neutron transport in nuclear fuels and the crystalline structure of materials, providing theoretical formalism for neutron scattering by crystals and exploring the effects of oxygen vibrations on crystal structures.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2021)
Review
Green & Sustainable Science & Technology
William R. Smith, Hamdah Tahir, Allan M. M. Leal
Summary: The need for chemical reaction equilibrium calculations in biomass gasification modeling and other fields is common. This review article addresses the contradictions in the literature regarding the stoichiometric (S) and non-stoichiometric (NS) formulations and provides a compatibility criterion for their equality. It clarifies misconceptions in the biomass gasification literature and demonstrates how both formulations can be viewed as strategies for minimizing Gibbs energy. Additionally, the review extends the S-NS compatibility criterion to an inequality, presenting a straightforward methodology for converting either formulation to a compatible formulation with an identical solution. The article also highlights the availability of open-source software for chemical equilibrium calculations, alleviating the need for researchers to create their own or use commercial codes.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Article
Nuclear Science & Technology
Jade J. Li, Samuel T. Murphy
Summary: Uranium nitride, a potential nuclear fuel, displays enhanced accident tolerance and its properties during operation have been studied using molecular dynamics. Introduction of hypostoichiometry as nitrogen antisites or nitrogen vacancy defects increases nitrogen diffusivity and decreases activation energy, with good agreement found between predicted activation energies and experimental observations in samples containing antisite defects.
PROGRESS IN NUCLEAR ENERGY
(2021)
Article
Materials Science, Multidisciplinary
L. Yang, B. D. Wirth
Summary: The stability and structure of low sigma value tilt grain boundaries in UO2 were investigated using molecular statics/dynamics simulations. Density functional theory (DFT + U) calculations showed that a defective triangle-like pattern in the E5(310) boundary was preferred over an oxygen-ring pattern. The incorporation energy profiles indicated that Xe interstitial sites at grain boundaries were energetically favorable compared to the bulk, while Xe incorporation in some Schottky defects or uranium vacancy sites at certain boundaries was energetically unfavorable. However, in general, Xe and its complexes tended to segregate to grain boundaries.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Chemistry, Analytical
Yunfeng Du, Hao Tang, Lang Shao, Rui Gao, Yiming Ren, Zhen Qin, Jiaolai Jiang, Junsheng Liao
Summary: A new method for fabricating stoichiometric uranium dioxide powder was proposed in this paper, which involved the direct electro-reduction of triuranium octoxide in molten salt. The quality of the prepared sample was verified using XRD, Raman spectroscopy, and TG/DSC measurements.
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
(2022)
Article
Materials Science, Multidisciplinary
Nikita A. Liedienov, Ziyu Wei, Viktor M. Kalita, Aleksey V. Pashchenko, Quanjun Li, Igor V. Fesych, Vitaliy A. Turchenko, Changmin Hou, Xu Wei, Bingbing Liu, Aleksey T. Kozakov, Georgiy G. Levchenko
Summary: This study investigated the structural, magneto-transport, and magnetocaloric properties of nanoscale manganite particles with strong spin-electron coupling. Complex behaviors related to spin, valence, and temperature were discovered.
APPLIED MATERIALS TODAY
(2022)
Article
Materials Science, Multidisciplinary
L. Yang, B. D. Wirth
Summary: The study investigates the microstructure evolution of uranium dioxide (UO2) due to xenon (Xe) accumulation through the growth of highly pressurized Xe bubbles using molecular dynamics simulations. Two stages characterized by bubble pressure are identified, with the evolution depending on the interatomic potentials and causing dislocations, phase transitions, and interfaces in UO2.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Review
Materials Science, Multidisciplinary
Mark Jolly, Laurens Katgerman
Summary: Over the last four decades, significant progress has been made in the modelling of casting processes, enabling a better understanding of physical phenomena and calculation of difficult-to-measure quantities. However, there is still room for improvement in accurately predicting casting performance and defects.
PROGRESS IN MATERIALS SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Megha Sanjeev, Mark R. Gilbert, Samuel T. Murphy
Summary: This study uses molecular dynamics simulations to investigate how the thermal conductivity of Li2TiO3 changes with different stoichiometries. The results show a significant decrease in thermal conductivity at room temperature, but deviations from stoichiometry have limited impact on thermal conductivity at higher temperatures.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Chemistry, Physical
Daniel Mutter, Roland Schierholz, Daniel F. Urban, Sabrina A. Heuer, Thorsten Ohlerth, Hans Kungl, Christian Elsaesser, Ruediger-A. Eichel
Summary: The defect chemistry of perovskite compounds is closely related to the stoichiometry and valence states of transition-metal ions, allowing for tuning catalytic properties through defect engineering. Combining theoretical calculations and experimental methods, this study investigates the feasibility of manipulating the valence state of iron and the concentration of point defects by synthesizing La-deficient LFO. The results suggest that significant compositional deviations from stoichiometric LFO are not expected by varying the conditions of oxidic precursor compounds in solid-state processing routes.
CHEMISTRY OF MATERIALS
(2021)
Article
Chemistry, Physical
William D. Neilson, James T. Pegg, Helen Steele, Samuel T. Murphy
Summary: The study determined point defect concentrations in PuO2 by combining DFT defect energies and empirical potential calculations of vibrational entropies, finding that the defect chemistry is dominated by oxygen vacancies and interstitials. It also observed that oxygen interstitials only exist in very low concentrations in hyper-stoichiometric PuO2+x, with small degrees of hyper-stoichiometry favored by low temperatures.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Marjorie Bertolus, Michel Freyss, Boris Dorado, Guillaume Martin, Kiet Hoang, Serge Maillard, Richard Skorek, Philippe Garcia, Carole Valot, Alain Chartier, Laurent Van Brutzel, Paul Fossati, Robin W. Grimes, David C. Parfitt, Clare L. Bishop, Samuel T. Murphy, Michael J. D. Rushton, Dragos Staicu, Eugen Yakub, Sergii Nichenko, Matthias Krack, Fabien Devynck, Raoul Ngayam-Happy, Kevin Govers, Chaitanya S. Deo, Rakesh K. Behera
JOURNAL OF NUCLEAR MATERIALS
(2015)
Article
Physics, Applied
E. S. Yakub
LOW TEMPERATURE PHYSICS
(2015)
Article
Physics, Applied
Eugene Yakub
JOURNAL OF LOW TEMPERATURE PHYSICS
(2017)
Article
Thermodynamics
Eugene S. Yakub, Lydia N. Yakub
FLUID PHASE EQUILIBRIA
(2013)
Article
Chemistry, Physical
Lydia Yakub, Eugene Yakub
JOURNAL OF CHEMICAL PHYSICS
(2012)
Editorial Material
Physics, Applied
Mikhail A. Strzhemechny, Eugene S. Yakub
LOW TEMPERATURE PHYSICS
(2013)
Article
Physics, Applied
E. S. Yakub
LOW TEMPERATURE PHYSICS
(2013)
Article
Physics, Applied
E. S. Yakub
LOW TEMPERATURE PHYSICS
(2019)
Article
Engineering, Chemical
Eugene Yakub, Samuel E. Agarry, Felix Omoruwou, Chiedu N. Owabor
PARTICULATE SCIENCE AND TECHNOLOGY
(2020)
Article
Physics, Applied
E. S. Yakub, L. N. Yakub
LOW TEMPERATURE PHYSICS
(2020)
Article
Physics, Applied
E. S. Yakub, L. N. Yakub
Summary: The Mayer group expansion method was applied to predict the locations of polymorphic phase transition lines in highly compressed nitrogen solid. The influence of intermolecular correlations on the temperature dependence of phase transition pressures was estimated.
LOW TEMPERATURE PHYSICS
(2022)
Review
Physics, Applied
E. Yakub, L. Yakub
Summary: This study reviews recent experimental results and computer modeling of the behavior of helium in uranium-based nuclear fuels. The potential models of interaction between helium, uranium, and oxygen ions are discussed, as well as the application and prospects of computer simulation methods in predicting important properties of helium in uranium dioxide solid solutions, such as solubility and diffusion coefficients.
LOW TEMPERATURE PHYSICS
(2022)
Article
Physics, Applied
E. S. Yakub
Summary: The Mayer group expansion method is extended to low-temperature solids in order to predict the polymorphic transition line between cubic and orthorhombic phases in highly compressed uranium dioxide. The temperature dependence of the transition pressure and volume changes is evaluated and compared with experimental data and ab initio predictions.
LOW TEMPERATURE PHYSICS
(2023)
Article
Physics, Applied
E. S. Yakub, L. N. Yakub
LOW TEMPERATURE PHYSICS
(2020)
Article
Thermodynamics
Eugene S. Yakub
HIGH TEMPERATURES-HIGH PRESSURES
(2014)
Article
Materials Science, Multidisciplinary
Liuming Wei, Jingwen Li, Yonggang Li, Qirong Zheng, Fan Cheng, Chuanguo Zhang, Jingyu Li, Gaofeng Zhao, Zhi Zeng
Summary: This study investigates the influence of He-V complexes on H behaviors on different W surfaces using DFT calculations. The results show that H dissolution is most difficult but H trapping is easiest on the W (110) surface, while the opposite is true on the W (111) surface. Moreover, the presence of He-V complexes increases the difficulty of H diffusion from bulk to surface and desorption.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Yan Meng, Song Zeng, Chen Chen, Chaowen Zhu, Huahai Shen, Xiaosong Zhou, Xiaochun Han
Summary: The characteristics of magnetron sputtered Cr coatings vary with different temperature, bias voltage, and pressure. Coatings with random orientation, good crystallinity, and small grain size exhibit favorable oxidation behavior, while coatings with strong (200) texture, poor crystallinity, and large grains have many intrinsic defects that are detrimental to the protection property of the Cr coatings.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Xinyuan Xu, Zefeng Yu, Wei-Ying Chen, Aiping Chen, Arthur Motta, Xing Wang
Summary: This study presents an automated approach for characterizing grain morphology in TEM images recorded during ion irradiation. By combining a machine learning model and a computer vision algorithm, comparable results to human analysis can be achieved with significantly reduced analysis time. Researchers can train their own models following the procedures described in this study to automate grain morphology analysis of their own TEM images.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Shihao Wu, Dong Wang, Yapei Zhang, Koji Okamoto, Marco Pellegrini, Wenxi Tian, Suizheng Qiu, G. H. Su
Summary: The oxidation and degradation mechanisms of Cr coating on Zr alloy cladding under high temperature steam atmosphere are summarized, and a mathematical analysis model is established to predict the changes in coating thickness. The model is applied in the analysis of structure evolution under different conditions.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
V. Diaz-Mena, J. de Prado, M. Roldan, I. Izaguirre, M. Sanchez, M. Rieth, A. Urena
Summary: The brazeability of a cupronickel alloy was evaluated as a filler alloy for high-temperature joining of tungsten to steel. The study investigated the brazing conditions and the impact of the selected filler on the joint quality using numerical software. The results showed different metallurgical interactions and diffusion phenomena between the filler alloy and the base materials at different temperatures. The study emphasized the importance of selecting a suitable filler to mitigate residual stresses in the joints.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Pengcheng Zhu, Yajie Zhao, Yan-Ru Lin, Jean Henry, Steven J. Zinkle
Summary: This study investigates the effect of heavy-ion irradiation on radiation hardening in high-purity binary alloy Fe18Cr. Nanoindentation testing and high-quality TEM imaging were conducted to extract hardness and microstructure information. The strength factor was accurately calculated based on the detailed TEM characterization of irradiated microstructures, and a refined hardening superposition method was applied to quantify the mechanical properties of ion-irradiated materials.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Bin Wu, Haixia Ning, Hanzhen Zhu, Jianjun Chen, Kang Wang, Daiyu Zhang, Fu Wang, Qilong Liao
Summary: This study discusses the effects of ZrO2 and B2O3 on the phase composition and properties of SAP-based glass-ceramics. The results show that ZrO2 addition improves the formation of NZP phase while restricting the crystallization of AlPO4 phases. The correct ratios of ZrO2 and B2O3 allow only the formation of NZP phase within the SAP glass.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Hwasung Yeom, Greg Johnson, Benjamin Maier, Tyler Dabney, Kumar Sridharan
Summary: Cr-Nb bilayer coatings were developed using cold spray deposition to improve the limiting operational temperature of Cr-coated Zr-alloy system. The coatings exhibited outstanding oxidation resistance at high temperatures and formed continuous intermetallic compound layers at the interfaces.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Padhraic L. Mulligan, Andrew T. Nelson, Chad M. Parish, Patrick A. Champlin, Xiang Chen, Daniel Morrall, Jason M. Harp
Summary: Environmental barrier coatings are being developed to reduce oxidation and embrittlement in Zr-based materials. Chromium nitride is a candidate for this application, but understanding its impact on irradiation-induced creep and microstructure is critical.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Dexuan Yan, Xinlei Cao, Ke Shen
Summary: This study investigated the purification mechanism of polycrystalline graphite by comparing IG-11 graphite with IG-110 nuclear grade graphite. The analysis revealed that metallic impurities in IG-11 were primarily segregated within graphite porosities, while IG-110 demonstrated a significant reduction in impurities. This research contributes to the development of innovative graphite purification techniques for greater purity and stronger oxidation resistance.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Wei Xu, Wei Peng, Lei Shi, Qi Sun
Summary: This paper investigates the oxidation and shape evolution of matrix graphite in high temperature gas-cooled reactors during air-ingress accidents. A reaction kinetics model is established and computational fluid dynamics with a dynamic mesh method is used to simulate the oxidation process. The results show that the geometric shape of graphite changes significantly with increasing flow rate, and the graphite pebbles tend to form a structure with a narrow front and wide tail.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Allison Harward, Casey Elliott, Michael Shaltry, Krista Carlson, Tae-Sic Yoo, Guy Fredrickson, Michael Patterson, Michael F. Simpson
Summary: This paper investigates the hygroscopic properties of eutectic LiCl-KCl absorbed into zeolite-4A. The study finds that water absorption and corrosion worsen with increasing salt loading. It also suggests that the salt can be stored in a non-inert atmosphere for a certain period of time.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Takaaki Koyanagi, Xunxiang Hu, Christian M. Petrie, Gyanender Singh, Caen Ang, Christian P. Deck, Weon-Ju Kim, Daejong Kim, James Braun, Yutai Katoh
Summary: This study provides critical experimental data on the effects of irradiation on the hermeticity of SiC composite cladding, finding that irradiation can cause a decrease in hermeticity and cracking, and coating the outer surface can mitigate the cracking issue.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
S. Krat, A. Prishvitsyn, Yu. Gasparyan
Summary: This study proposes a probabilistic and diffusion-based model to describe the co-deposition of multiple hydrogen isotopes with slowly grown metal layers. The model calculates the relative concentrations of different hydrogen isotopes in the co-deposited metal layers. It is found that if hydrogen isotopes have different detrapping energies, only the isotope with the highest detrapping energy shows a monotonic decrease in concentration with deposition temperature. Furthermore, the study evaluates the uncertainty of tritium concentration in the co-deposited layer based on the uncertainty in detrapping energy of tritium and deuterium, predicting a >10% tritium concentration uncertainty for a 0.01 eV difference.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Tijo Vazhappilly, Arup Kumar Pathak
Summary: This study investigates the effect of Ce atom substitution in UO2 on its thermophysical properties using density functional theory. The results show that the Ce substitution levels and the oxidation state of Ce/U atoms strongly influence the band structure and specific heat capacity of the UO2 lattice. These findings provide important insights into the fuel properties of UO2 under reactor conditions.
JOURNAL OF NUCLEAR MATERIALS
(2024)
