Article
Materials Science, Multidisciplinary
Julia A. Baimova, Leysan Kh Galiakhmetova, Radik R. Mulyukov
Summary: This work investigates the mechanical behavior of diamond-like phases under hydrostatic tension and compression, using atomistic simulations to calculate elastic constants and demonstrate that new carbon allotropes can sustain high applied compression like diamond. The diamond-like phases are confirmed to be high-strength structures with promising application prospects.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Materials Science, Ceramics
Lorena B. Caliman, Andre Luiz da Silva, Douglas Gouvea
Summary: Magnesium aluminate spinel (MAS) is widely used in technological applications due to its excellent properties and stability. This study reports the synthesis of nonstoichiometric single-phase spinel nanopowders at low temperatures and investigates the impact of chemical distribution on their stability.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Materials Science, Multidisciplinary
B. V. Politov, A. M. Shalamova, I. R. Shein, A. Yu. Suntsov
Summary: A perovskite-like oxide, LaCu0.5Mn0.5O3-delta (LCMO) was synthesized and characterized using X-ray powder diffraction and high-resolution transmission electron microscopy, revealing disordered cation arrangement in the crystal structure. Reduction annealing was found to lead to non-zero oxygen vacancy concentrations in the LCMO, modifying its low-temperature magnetic properties. Density functional theory was employed to assess the symmetry of the lattice and analyze the effects of cationic order on electronic and magnetic structure. The results provide insights into the defect formation and equilibration in LCMO, and the interpretation of dielectric and optical properties of similar oxide materials.
Article
Chemistry, Physical
L. Pan, S. Sholom, S. W. S. McKeever, L. G. Jacobsohn
Summary: This study investigated magnesium aluminum spinels with different Mg:Al ratios for optically stimulated luminescence dosimeters, finding that stoichiometric spinel showed superior OSL dose response, stability, and sensitivity compared to other ratios.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Rongyang Qiu, Yangchun Chen, Xichuan Liao, Xinfu He, Wen Yang, Wangyu Hu, Huiqiu Deng
Summary: The development of V-Ti-Ta interatomic potential is a significant step towards the atomic-scale investigation of V-based alloys, which fits well with experimental data and DFT calculations and can be used for atomistic simulations of point defects evolution.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Chemistry, Physical
Mads-Peter V. Christiansen, Nikolaj Ronne, Bjork Hammer
Summary: Modeling and understanding material properties from first principles requires knowledge of atomistic structure. The rise of machine learning techniques in materials science has accelerated structure searches. This paper introduces the customizable Atomistic Global Optimization X (AGOX) framework and code for efficient building and testing of global optimization algorithms.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Jing Wei, Zhengtao Zhang, Fei Shen, Chengkan Lv
Summary: This paper proposes a mask-guided background-preserving defect generation method to solve the problems of current defect generation methods and achieve better results in defect segmentation tasks.
Article
Chemistry, Physical
Z. Zhen, S. Y. Wang, R. L. Liu, Z. C. Meng, C. Y. Teng, D. S. Xu, C. G. Bai, Y. W. Zhang, H. Wang, R. Yang
Summary: Super-dislocations play a significant role in the plasticity of intermetallic compounds, especially in terms of fatigue and creep properties. However, the study of super-dislocation dipoles has been limited due to technical challenges in both experimental observation and theoretical computation. This work systematically investigates superdislocation dipoles in M3Al (M=Ni, Fe, Ti) using atomistic simulations, considering various super-lattice types, dipole heights, orientations, and annealing temperatures. The results show that the relative stability of super-dipoles increases with dipole height, and there are numerous pathways with low activation energy for the transformation from super-dipoles to point defects. The findings can be applied in mesoscale or constitutive models to evaluate the influence of super-dislocation self-interaction on mechanical properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Electrochemistry
Yanan Li, Hong Gao, Wude Yang
Summary: This study systematically explores the effect of non-metallic element (F, Cl, Br, I, C, and N) doping modification on lithium titanate oxide (LTO) electrode materials. The results show that C, N, and Br dopants play a significant role in improving the electrochemical performance of LTO, with each dopant having different advantages. C dopant reduces particle size and agglomeration, Br dopant increases unit cell volume, and N dopant forms oxygen vacancies and TiN structures. In terms of electrochemical performance, C dopant reduces charge transfer resistance, Br dopant improves capacity at low rates, and N dopant enhances high rate performance of LTO. This study provides new insights into optimizing the electrochemical performance of lithium titanate by adjusting its morphology, crystal structure, and electronic structure based on non-metallic materials' characteristics.
ELECTROCHIMICA ACTA
(2022)
Article
Materials Science, Multidisciplinary
Sara Fazeli, Pascal Brault, Amael Caillard, Anne-Lise Thomann, Eric Millon, Soumya Atmane, Christophe Coutanceau
Summary: In this study, the impact of vacancy defects and nitrogen doping on the properties of tetragonal zirconia (t-ZrO2) was investigated. Oxygen-deficient t-ZrO2 showed a smaller bandgap and enhanced plasticity, while nitrogen-doped t-ZrO2 had a smaller bandgap but weaker plasticity. The results suggest that oxygen-deficient t-ZrO2 is a promising semiconductor material for photoelectrochemical energy conversion applications due to its smaller bandgap and higher plasticity.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Kohei Shimokawa, Taruto Atsumi, Norihiko L. Okamoto, Tomoya Kawaguchi, Susumu Imashuku, Kazuaki Wagatsuma, Masanobu Nakayama, Kiyoshi Kanamura, Tetsu Ichitsubo
Summary: This study demonstrates a design concept for high-performance cathode materials by selecting an element to destabilize the rocksalt-type structure and utilizing the defect-spinel-type structure, leading to excellent cycle performance of magnesium rechargeable batteries.
ADVANCED MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Joshua Masinde Kundu, Ting Liu, Jia Tao, Ya-Xian Fan, Zhi-Yong Tao
Summary: This study investigates the localized defect states of liquid surface waves in non-Bragg periodic structures. It is found that the position of the defect affects the magnitude of the transmission coefficient of the defect mode, while the frequency of the defect mode remains independent of the defect location. Control of the mode frequency is possible by manipulating the effective filling fraction of the periodic structures.
RESULTS IN PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Erwin Douguet-Bronnec, Jacques Fouletier, Franck Fournet-Fayard, Marlu Cesar Steil, Philippe Garcia
Summary: This study reports attempts at determining the evolution of oxygen activity in hyper-stoichiometric uranium dioxide for very low deviation from stoichiometry. Solid-state oxidation cycles and oxygen activity measurements were performed on a dense polycrystalline uranium oxide sample, and the data were subsequently analyzed using an oxygen point defect model. The results show that the model accurately reproduces the observed trends in the experimental data.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Multidisciplinary Sciences
Fenghua Nie, Wei Jian, Denvid Lau
Summary: This study investigates the self-healing properties of graphene-modified asphalt through molecular dynamics simulations. The results show that the location of graphene significantly affects the self-healing behaviors of asphalt, with graphene near the crack surface greatly accelerating the healing process. A deeper understanding of the self-healing mechanism of asphalt contributes to improving its self-healing properties and developing durable asphalt pavements.
JOVE-JOURNAL OF VISUALIZED EXPERIMENTS
(2022)
Article
Chemistry, Multidisciplinary
Zhili Hu, Minmin Xue, Zhuhua Zhang, Wanlin Guo, Boris I. Yakobson
Summary: Chemical growth of two-dimensional (2D) materials with controlled morphology on undulated substrates can lead to a variety of topological defects and grain boundaries. This study uses a Monte Carlo method to show that 2D materials grown on periodically undulated substrates follow three distinct growth modes: defect-free conformal, defect-free suspension, and defective conformal. The growth on non-Euclidean surfaces can cause stress accumulation and eventually result in the suspension of the materials, leading to the formation of grain boundaries.
Review
Multidisciplinary Sciences
Hanaa A. Galeb, Emma L. Wilkinson, Alison F. Stowell, Hungyen Lin, Samuel T. Murphy, Pierre L. Martin-Hirsch, Richard L. Mort, Adam M. Taylor, John G. Hardy
Summary: Melanins are biopolymers with diverse origins, chemical compositions, and functions, offering opportunities for applications in materials science, particularly in medical and technical fields. Analytical techniques are crucial for studying melanins in multidisciplinary contexts, promoting their use as sustainable resources for advanced biotechnological applications and contributing to the achievement of the United Nations Sustainable Development Goals.
Article
Chemistry, Multidisciplinary
John G. Hardy, Stephanie Sdepanian, Alison F. Stowell, Amal D. Aljohani, Michael J. Allen, Ayaz Anwar, Dik Barton, John Baum, David Bird, Adam Blaney, Liz Brewster, David Cheneler, Olga Efremova, Michael Entwistle, Reza N. Esfahani, Melike Firlak, Alex Foito, Leandro Forciniti, Sydney A. Geissler, Feng Guo, Rania M. Hathout, Richard Jiang, Punarja Kevin, David Leese, Wan Li Low, Sarah Mayes, Masoud Mozafari, Samuel T. Murphy, Hieu Nguyen, Chifundo N. M. Ntola, George Okafo, Adam Partington, Thomas A. K. Prescott, Stephen P. Price, Sherif Soliman, Papri Sutar, David Townsend, Patrick Trotter, Karen L. Wright
Summary: Multidisciplinary teaching improves learners' affective and cognitive learning abilities, and the inclusion of chemistry as a discipline in higher education is increasingly important.
JOURNAL OF CHEMICAL EDUCATION
(2021)
Article
Materials Science, Multidisciplinary
Michael J. Watts, Peter Hatton, Roger Smith, Tom Fiducia, Ali Abbas, Rachael Greenhalgh, John M. Walls, Pooja Goddard
Summary: Cadmium telluride is a key material in second generation thin-film photovoltaic technology, with a high solar cell conversion efficiency achieved through activation treatment with CdCl2. Chlorine atoms concentrated at grain boundaries after treatment, and density functional theory calculations show their stabilization compared to bulk CdTe. These findings suggest that the passivation of single-particle levels by halogens is the primary cause of the efficiency enhancement in chlorine treatment.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Nuclear Science & Technology
Megha Sanjeev, Mark R. Gilbert, Samuel T. Murphy
Summary: The study demonstrates the high anisotropy in the thermal conductivity of lithium metatitanate, Li2TiO3, through classical simulation methods, and suggests potential applications in breeder blanket design. It also lays the groundwork for further investigating the impact of defects on the thermal conductivity of Li2TiO3.
FUSION ENGINEERING AND DESIGN
(2021)
Article
Nuclear Science & Technology
Mark James Wootton, John D. Andrews, Adam L. Lloyd, Roger Smith, A. John Arul, Gopika Vinod, M. Hari Prasad, Vipul Garg
Summary: A nuclear reactor's safe operation relies on maintaining coolant circulation and core reactivity. Traditional methods like Fault Trees and Event Trees have limitations in modeling aging processes and complex maintenance strategies, making Petri Nets a more suitable alternative.
ANNALS OF NUCLEAR ENERGY
(2022)
Article
Materials Science, Multidisciplinary
I Brown, R. Smith, S. D. Kenny
Summary: A reactive field force potential has been created to study the structural effects of low percentage dopant aluminium in a zinc oxide system. The model reveals that substitution becomes more stable as the energy increases.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2022)
Article
Physics, Applied
R. L. Gray, M. J. D. Rushton, S. T. Murphy
Summary: The advent of high-temperature superconductors has provided the possibility of constructing smaller and cheaper fusion reactors. However, the impact of high-energy neutrons from fusion reactions on the superconductors needs to be addressed. This study uses molecular dynamics simulations to investigate the radiation-induced modifications on the crystal structure of YBa2Cu3O7, and the results show the formation of amorphous regions decorated with Cu and O defects.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2022)
Correction
Multidisciplinary Sciences
Peter Hatton, Michael J. Watts, Ali Abbas, John M. Walls, Roger Smith, Pooja Goddard
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Liangzhi Tan, Kawsar Ali, Partha Sarathi Ghosh, Ashok Arya, Ying Zhou, Roger Smith, Pooja Goddard, Dhinisa Patel, Hamed Shahmir, Amy Gandy
Summary: This study combines DFT calculations and experimental techniques to investigate the formation of equiatomic quaternary low-activation high entropy alloys (HEAs) for nuclear fission/fusion applications. The study screens the formation of possible alloys using DFT techniques and confirms the formation of alloys through experiments. Different alloys have different crystal structures.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Operations Research & Management Science
Mark James Wootton, Ying Zhou, John D. Andrews, Roger Smith, John Arul, Gopika Vinod, Hari Prasad Muruva, Vipul Garg
Summary: This paper presents an optimization methodology using the primary coolant circulation system of a nuclear reactor as a case study. The goal is to find combinations of selected design and maintenance parameters that maximize reactor safety and minimize monetary expenditure. The parameter space is sampled using a Monte Carlo method and Petri net modeling is used to predict the performance of each option. The optimal solutions are then extracted through computation of the Pareto front, with further analysis conducted on parameter sets of interest.
APPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY
(2022)
Article
Chemistry, Physical
Florian Bocchese, Iain Brown, David Cornil, Pavel Moskovkin, Jerome Muller, Steven David Kenny, Roger Smith, Stephane Lucas
Summary: This study investigates the growth process and properties of Ag films on ZnO using magnetron sputtering through thin film growth simulations. A new method to account for defects generated by magnetron sputtering has been developed. The simulated conductivity matches experimental results with the difference attributed to electron scattering at grain boundaries. The study also shows that a patterned substrate does not increase conductivity but leads to controlled growth of small islands suitable for other applications.
APPLIED SURFACE SCIENCE
(2023)
Article
Physics, Condensed Matter
Peter Hatton, Michael Watts, Ying Zhou, Roger Smith, Pooja Goddard
Summary: The doping of CdTe with As is a promising method for increasing cell efficiency. Calculations using Density Functional Theory show that isolated As atoms can diffuse easily in bulk CdTe, indicating unhindered transport. However, substitutional arsenic in bulk CdTe has little effect on the band gap. In contrast, arsenic in grain boundaries introduces defect states into the band gap, suggesting a doping strategy involving chlorine saturation before introducing arsenic atoms.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Chemistry, Physical
Elanor Murray, Ying Zhou, Peter Slater, Roger Smith, Pooja Goddard, Helen Steele
Summary: This study investigates the diffusion and clustering of helium in plutonium dioxide using molecular dynamics and barrier searching methods. The results show that helium diffusion in perfect PuO2 is limited at low temperatures but increases with the presence of oxygen vacancies. Oxygen vacancy assisted inter-site hopping is the key diffusion mechanism for helium. Helium clusters with a He : vacancy ratio below 1 : 1 form over nanosecond time scales. Schottky defects act as seed points for helium cluster growth.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Ying Zhou, Prashanth Srinivasan, Fritz Kormann, Blazej Grabowski, Roger Smith, Pooja Goddard, Andrew Ian Duff
Summary: Multi-principal-component alloys, such as high entropy alloys (HEAs), have unique properties and a vast compositional space, making them attractive for alloy design. This study focuses on using computational materials design to investigate the high-temperature properties of HEAs, specifically the full free energy surface and thermodynamic properties. The developed approach, based on density-functional theory and machine learning, shows a significant speed-up and accurate predictions of high-temperature free energy. The study is performed on an equiatomic HEA composition, which may have potential applications in next generation fission and fusion reactors.
Proceedings Paper
Energy & Fuels
R. Greenhalgh, P. Hatton, V Kornienko, A. Abbas, P. Goddard, R. Smith, J. Bowers, J. M. Walls
Summary: The introduction of selenium to thin film CdTe photovoltaic devices, through deposition of CdSe on the buffer layer, has significantly increased the conversion efficiency by inter-diffusing the two layers during the cadmium chloride activation. However, magnetron sputtering of CdSe may lead to deleterious voids in the devices, caused by the accumulation of argon into bubbles during activation, potentially resulting in blister formation and film surface exfoliation.
2021 IEEE 48TH PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)
(2021)
Article
Materials Science, Multidisciplinary
Nizar Lefi, Salem Neily, Roland Bonnet
Summary: This paper investigates the elastic field in a bi-material crystal with an angular dislocation line with one branch placed in the crystal and the other along a strongly bound or welded interface. The analysis formulates the elastic field of a closed dislocation loop and solves it using the knowledge of the Green's tensor of the bi-material. The study provides a faster calculation method and has important implications for solving interfacial angular dislocation problems.
PHILOSOPHICAL MAGAZINE
(2024)
