Article
Materials Science, Ceramics
Man Zhang, Jianhua Liu, Junwen Zhou
Summary: The effect of Eu2O3 doping amount on the densification behavior of MgAl2O4 and its corrosion resistance to aluminum electrolyte was studied. The results showed that Eu2O3 doping contributed to the densification of MgAl2O4, and the sample with 3 wt.% Eu2O3 had the highest relative density and hardness. Additionally, this sample exhibited the best corrosion resistance to aluminum electrolyte.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Peter A. Schultz, Renee M. Van Ginhoven, Arthur H. Edwards
Summary: By employing the LMCC method, this study provides a comprehensive analysis of the atomic structure and energy levels of point defects in cubic silicon carbide. The modified Jost screening model is validated for evaluating polarization energy induced by charged defects. The LMCC-PBE approach successfully eliminates the band gap problem and is consistent with hybrid-exchange functional results.
Article
Engineering, Biomedical
Mehran Ghodrati, Seyed Mahdi Rafiaei, Lobat Tayebi
Summary: In this study, magnesium aluminate spinel (MgAl2O4) nanoparticles were synthesized using a combustion approach and then incorporated into PLA to prepare scaffolds. The crystal structure, microstructure, biodegradability, and thermal characteristics of the materials were investigated using XRD, FESEM, ICP, STA, and compressive strength analyses. The results showed that PLA/6 wt% MgAl2O4 scaffolds exhibited the highest compressive strength. Immersion of the scaffolds in SBF revealed improved biodegradability, while improper particle dispersion occurred at higher MgAl2O4 loadings.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Markus Mader, Richard Prediger, Karl G. Schell, Gabriela Schmidt, Alex Dorn, Sophie Jenne, Sebastian Kluck, Leonhard Hambitzer, Manuel Luitz, Claudia Schwarz, Marcel Milich, Christian Greiner, Bastian E. Rapp, Frederik Kotz-Helmer
Summary: This study develops a thermoplastic nanocomposite that can be shaped into transparent ceramics using polymer injection molding. The process involves several steps to achieve high density, high optical transmission, and high mechanical strength in the transparent ceramics. By making transparent ceramics accessible to high-throughput polymer processing techniques, this research enables fast and cost-efficient manufacturing of macroscopic and microstructured components, opening up a wide range of potential applications.
Article
Chemistry, Physical
Xun Xu, Tingyu Liu, Qiuyue Li
Summary: The study investigates the relative stability and optimal positions of intrinsic defects and Cu defects in LiAlO2 crystal, showing that Cu-Li is most stable in O-rich conditions and energetically preferred under O-poor conditions, leading to the optimum OSL signal. Furthermore, other trapped-hole centers such as Cu-Li-V-Li and STH in the crystal also play a role and need to be considered for overall crystal performance.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Ceramics
Peiying Wang, Juanli Zhao, Yun Fan, Wei Zhang, Yuanyuan Cui, Liangmiao Zhang, Bin Liu, Hongqiang Nian, Yiran Li
Summary: The composition-dependent point defect types and formation energies of RE2Hf2O7 were systematically investigated by first-principles calculations, revealing different dominant defect complexes under stoichiometric and non-stoichiometric conditions. The migration energy barriers for oxygen ions in pyrochlore hafnates were calculated, suggesting potential oxygen ionic conductivity and proposing a defect engineering strategy based on the findings.
CERAMICS INTERNATIONAL
(2021)
Article
Chemistry, Physical
Xiuyi Liu, Zhe Chen, Wen Yan, Jingran Wang, Sanbao Ma, Guangqiang Li
Summary: Lightweight design and preparation of refractories can contribute to energy saving and emissions reduction in high temperature furnaces. Two lightweight periclase-magnesium aluminate spinel refractories were prepared using microporous aggregates and compared to commercial dense refractories. The results showed that the lightweight specimens had increased strength, reduced thermal conductivity, and improved microstructure due to the microstructure of the microporous aggregates.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Ceramics
Somnath Sinhamahapatra, Chandrima Ghosh, Himansu Sekhar Tripathi, Sunanda Mukhopadhyay
Summary: The magnesium aluminate spinel was prepared from constituent oxides through a solid-state sintering process at temperatures ranging from 1550 to 1700 degrees C in a normal air atmosphere. The addition of TiO2 and Yb2O3 improved the densification and mechanical properties of the magnesia-rich spinel, with Yb2O3 showing better performance in room temperature flexural strength.
CERAMICS INTERNATIONAL
(2021)
Article
Materials Science, Ceramics
Ming Shi, Ying Li, Junjie Shi
Summary: A novel method for fabricating periclase and magnesium aluminate spinel refractory from secondary aluminum dross was proposed. The study analyzed the fabrication mechanism and studied the effects of MgO addition and sintering temperature on the properties of refractories. The results showed significant improvement in purity, crystallinity, densification, flexural strength, and impact toughness with increasing sintering temperature and MgO addition.
CERAMICS INTERNATIONAL
(2022)
Article
Physics, Applied
Alain Chartier, Paul Fossati, Laurent Van Brutzel, Orest Dorosh, Jacek Jagielski
Summary: The response of MgO periclase to irradiation was investigated using molecular dynamics simulations. The simulated lattice and volume swellings matched well with experimental measurements. Below 0.2 dpa, dislocation loops were formed from point defect clusters, consisting of magnesium and oxygen interstitials. Very small 1/2 110 loops in {001} planes acted as seeds for the growth of dislocation loops in {110}, {001}, and {111} planes. Above 0.2 dpa, lattice swelling decreased relative to the formation of less dense dislocation forests, while volume swelling increased rapidly due to significant voids of vacancies, up to 32 vacancies.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Ceramics
Aref Basiri, Amir Hossein Nassajpour-Esfahani, Mohammad Reza Haftbaradaran-Esfahani, Amir Alhaji, Ali Shafyei
Summary: This study investigated the granulation process of magnesium aluminate spinel powders using spray freeze drying method. The optimal amount of binder was found to be 3%, and the ideal solid load was determined to be 35 wt%, resulting in granules of 10-50 μm in size. Powder granulation increased density by approximately 20% and improved the in-line transmission for the IR range by over 15%.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
Ali Talimian, H. F. El-Maghraby, Monika Michalkova, Dusan Galusek
Summary: Adding 0.3 wt% lithium hydroxide can promote densification and limit grain growth of MgAl2O4, while also affecting the activation energy of sintering. The formation and disappearance of secondary phases were observed, with magnesium oxide and lithium aluminum oxide produced at certain temperatures.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
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
Chemistry, Physical
Neeraj Mishra, Guy Makov
Summary: The energetic and electronic properties of intrinsic point defects in germanium sulfide (GeS) were investigated using first-principles methods. It was found that the Schottky dimer (SD) is the most stable neutral defect, and Ge vacancies are the most stable defects in both Ge-rich and Ge-poor environments. GeS exhibits nonstoichiometric properties. The introduction of point defects affects the electronic structure of GeS, and Ge vacancies induce p-type conductivity.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Hu Tang, Zhenggang Jia, Bing Li, Huazhong Chen, Wenjie Yuan
Summary: In order to achieve the goal of dual-carbon, attention has been paid to induction furnaces with high efficiency and energy-saving advantages in the foundry and metallurgy industries. The service life and safety of induction furnaces strongly depend on the lining, which can be eroded and have poor slag resistance due to expansion and forward sintering. This study focused on the properties of alumina-magnesia-based dry ramming mixes and replaced calcined magnesia particles with a novel multi-component material, calcium magnesium aluminate (CaO-MgO-Al2O3, CMA), with a size of 200 mesh. The effects of CMA on the bulk density, apparent porosity, strength, and slag corrosion resistance of the dry ramming mixes were evaluated. The results showed that the addition of CMA reduced the slag penetration index and permanent linear change in the dry ramming mixes.
Article
Chemistry, Physical
William D. Neilson, Helen Steele, Samuel T. Murphy
Summary: This study predicts the effects of Am incorporation on the chemistry of PuO2 by establishing a point defect model, showing that high temperatures, low oxygen-to-metal ratios, or low Am concentrations favor the formation of Am in the +III oxidation state, increasing the material's conductivity.
JOURNAL OF PHYSICAL CHEMISTRY C
(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
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
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, Multidisciplinary
Mathew John Haskew, Benjamin Deacon, Chin Weng Yong, John George Hardy, Samuel Thomas Murphy
Summary: Utilizing information from experimental and computational studies, a simplified silk fibroin (SF) model has been created, enabling the application of molecular dynamic and density functional theory techniques to gain insight into SF-based materials. Evaluation of the computational model's secondary structure and water diffusion behavior provides important information for understanding the behavior of SF and similar biomaterials. Through further computational study and integration with experimental data, greater control over technologies related to SF may be achieved, impacting potential applications positively.
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.
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)