Article
Materials Science, Multidisciplinary
Cassidy M. Atkinson, Matthew C. Guziewski, Shawn P. Coleman, Sanjeev K. Nayak, S. Pamir Alpay
Summary: This study provides a detailed investigation on the formation energies of point defects and the stability of various dopants in bulk cubic silicon carbide and in grain boundaries, as well as the driving force of dopants towards grain boundaries. The results show different behaviors of dopants in grain boundaries, offering a chemical landscape for targeted materials development.
Article
Chemistry, Physical
Kirill A. Bokai, Viktor O. Shevelev, Dmitry Marchenko, Anna A. Makarova, Vladimir Yu Mikhailovskii, Alexei A. Zakharov, Oleg Yu Vilkov, Maxim Krivenkov, Denis V. Vyalikh, Dmitry Yu Usachov
Summary: Intercalation of oxygen can facilitate the detection of grain boundaries in polycrystalline graphene, providing insights into their morphology, and enabling visualization through various electron microscopy methods.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Benedikt Haas, Tara M. Boland, Christian Elsaesser, Arunima K. Singh, Katia March, Juri Barthel, Christoph T. Koch, Peter Rez
Summary: Phonon scattering at grain boundaries plays a crucial role in controlling the thermal conductivity of nanoscale devices. This study uses monochromated electron energy loss spectroscopy (EELS) in the scanning transmission electron microscope (STEM) to measure the 60 meV optic mode at grain boundaries in silicon at atomic resolution. The results show the existence of localized phonon modes and support the idea that grain boundaries can act as waveguides.
Article
Materials Science, Multidisciplinary
Timothy G. Lach, Annabelle G. Le Coq, Kory D. Linton, Kurt A. Terrani, Thak Sang Byun
Summary: The performance of the SiC fuel matrix is crucial in advanced gas-cooled high temperature reactors. A new additive manufacturing method combining 3D printing and chemical vapor infiltration was developed for SiC production. The study shows that 3D printed SiC exhibits behavior similar to SiC processed by other means, and electron energy loss spectroscopy analysis reveals similarities in radiation-induced swelling between the printed particles and the CVI matrix. Therefore, 3D printing could serve as a suitable processing technique for high-purity SiC for nuclear applications.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Sung Bo Lee, Seung Jo Yoo, Jinwook Jung, Heung Nam Han
Summary: The irradiation of high-energy particles can affect the grain-boundary structure of polycrystalline nuclear materials, with different reactions observed for different grain-boundary characteristics. By examining different types of grain boundaries in a model system, it was found that tilt boundaries became roughened while twist boundaries became faceted under the same irradiation conditions.
SCRIPTA MATERIALIA
(2021)
Article
Chemistry, Multidisciplinary
Kunyen Liao, Kiyou Shibata, Teruyasu Mizoguchi
Summary: Grain boundaries significantly affect the coefficient of thermal expansion in polycrystals. This study used EELS to directly measure CTE in different types of grain boundaries, revealing variations in thermodynamic properties and demonstrating the potential of EELS for probing local thermal properties at nanometer-scale resolution.
Article
Chemistry, Multidisciplinary
Penghui Li, Yeqiang Bu, Linyan Wang, Chong Wang, Junquan Huang, Ke Tong, Yujun Chen, Julong He, Zhisheng Zhao, Bo Xu, Zhongyuan Liu, Guoying Gao, Anmin Nie, Hongtao Wang, Yongjun Tian
Summary: Fracture behaviors in perfect and twinned B4C crystals were studied via in situ TEM mechanical testing. It was found that cracks preferentially initiated at the twin boundaries (TBs) and propagated along them, resulting in the fracture of B4C. The theoretical calculations also showed a softening effect of TBs on B4C, with amorphous bands preferentially nucleated at the TBs. These findings clarify the atomic arrangement and the role of planar defects in the failure of B4C.
ADVANCED MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Yuping Jia, Xiaojuan Sun, Zhiming Shi, Ke Jiang, Tong Wu, Hongwei Liang, Xingzhu Cui, Wei Lu, Dabing Li
Summary: Graphene inserted between metal ohmic electrode and SiC enhances the formation of carbon compounds to reduce contact resistance. The adjustable Fermi level of graphene enlarges the interface barrier to accelerate the separation of electron-hole pairs.
DIAMOND AND RELATED MATERIALS
(2021)
Article
Materials Science, Ceramics
Ryutaro Usukawa, Toshihiro Ishikawa
Summary: Si-Al-C-O materials are recognized as a good precursor for obtaining dense and heat-resistant SiC polycrystalline materials. The aluminum in SiC crystals plays a crucial role in creating a stable grain boundary at high temperatures, while most of the aluminum disappears during heat treatment, resulting in a dense SiC solid solution with uniformly distributed residual aluminum.
INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Xiaochen Li, Haibo Long, Jianfei Zhang, Dongfeng Ma, Deli Kong, Yan Lu, Shiduo Sun, Jixiang Cai, Xiaodong Wang, Lihua Wang, Shengcheng Mao
Summary: This study used in situ TEM observations to directly reveal dislocation nucleation at grain boundaries in nanocrystalline metals. The findings contradict the common hypothesis predicted by molecular dynamic simulations, showing that complete dislocations can be emitted from grain boundaries in small-grained structures.
MATERIALS CHARACTERIZATION
(2021)
Article
Chemistry, Multidisciplinary
James A. Quirk, Bin Miao, Bin Feng, Gowoon Kim, Hiromichi Ohta, Yuichi Ikuhara, Keith P. McKenna
Summary: An experimental and theoretical study of anatase grain boundaries fabricated by epitaxial growth on a bicrystalline substrate provides accurate atomic-scale models. The electronic structure in the vicinity of stoichiometric grain boundaries is relatively benign to device performance, but segregation of oxygen vacancies introduces barriers to electron transport. An intrinsically oxygen-deficient boundary exhibits charge trapping consistent with electron energy loss spectroscopy measurements.
Article
Materials Science, Ceramics
Christopher J. Marvel, Qirong Yang, Scott D. Walck, Kelvin Y. Xie, Kristopher D. Behler, Jerry C. LaSalvia, Masashi Watanabe, Richard A. Haber, Martin P. Harmer
Summary: The compositional analysis of boron carbide on nanometer length scales to interpret atomic mechanisms is challenging, but advancements in high-resolution microanalysis have allowed for accurate characterization of multiple generations of boron carbide. Zeta-factor microanalysis has been introduced as a powerful analytical framework, with three case studies demonstrating its application in determining accurate stoichiometry and quantifying segregation in boron carbide. Overall, the use of advanced analytical tools has improved the understanding of processing-microstructure-property relationships and the manufacturing of high-performance ceramics.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Multidisciplinary Sciences
Baokun Liang, Yingying Zhang, Christopher Leist, Zhaowei Ou, Miroslav Polozij, Zhiyong Wang, David Muecke, Renhao Dong, Zhikun Zheng, Thomas Heine, Xinliang Feng, Ute Kaiser, Haoyuan Qi
Summary: This paper presents the challenge of high-resolution imaging of organic 2D materials using transmission electron microscopes, and demonstrates the reduction of resolution gap between achievable resolution and instrumental limit by selecting the appropriate incident electron energy. The authors find that the highest resolution of 1.9 angstrom is achieved at 120 kV, and successfully detect interstitial defects and functional groups in 2D polymer thin films.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Qi Zhu, Qishan Huang, Haofei Zhou, Jiangwei Wang
Summary: This study reveals the fundamental influences of GB inclination on the deformation of curved dislocation-type GBs in face-centered cubic metals through in situ TEM nanomechanical testing and atomistic simulation. A inclination-governed GB model is established to predict the deformation behaviors of curved GBs, shedding light on the GB-mediated plasticity and the structural design of metallic materials.
JOURNAL OF MATERIALS RESEARCH
(2021)
Article
Chemistry, Analytical
Olivier De Castro, Jean-Nicolas Audinot, Hung Quang Hoang, Cherif Coulbary, Olivier Bouton, Rachid Barrahma, Alexander Ost, Charlotte Stoffels, Chengge Jiao, Mikhail Dutka, Michal Geryk, Tom Wirtz
Summary: The article introduces the use of magnetic sector secondary ion mass spectrometry (SIMS) on a widely used instrument, focused ion beam (FIB)-scanning electron microscopy (SEM), for nanoscale investigations. It provides a detailed description of the instrument's layout and performance, as well as the research results obtained in various fields. The system demonstrates versatile capability for high-performance correlative studies in materials science and life sciences.
ANALYTICAL CHEMISTRY
(2022)
Article
Physics, Applied
Dongzheng Chen, Ryan Jacobs, John Petillo, Vasilios Vlahos, Kevin L. Jensen, Dane Morgan, John Booske
Summary: A physics-based model is developed to accurately predict the emitted current from thermionic cathodes, spanning from temperature-limited to full-space-charge-limited regions. The model incorporates the cathode surface grain orientation and facet-orientation-specific work-function values to construct a nonuniform emission model for commercial dispenser cathodes. The predicted emission curves show excellent agreement with experimental results, providing a method to predict thermionic emission and improve the understanding of the relationship between emission and cathode microstructure.
PHYSICAL REVIEW APPLIED
(2022)
Article
Materials Science, Multidisciplinary
Jingrui Wei, Ben Blaiszik, Aristana Scourtas, Dane Morgan, Paul M. Voyles
Summary: The information content of atomic-resolution STEM images can be summarized by a few parameters, with column position being the most significant. Neural networks have been used to automatically locate atomic columns in STEM images, resulting in numerous NN models and training datasets. In this study, a benchmark dataset of simulated and experimental STEM images was developed to evaluate the performance of recent NN models for atom location. The models showed high performance for images of varying quality and crystal lattices. However, they performed poorly for images outside the training data, such as interfaces with large difference in background intensity. The benchmark dataset and models are available through the Foundry service.
MICROSCOPY AND MICROANALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Jun Meng, Mehrdad Abbasi, Yutao Dong, Corey Carlos, Xudong Wang, Jinwoo Hwang, Dane Morgan
Summary: This study characterized the structural and electronic properties of a-TiO2 thin films grown on Si by ALD, revealing the medium-range ordering in the film and establishing a realistic atomic model. Additionally, an improved multi-objective optimization package, StructOpt, was provided for structure determination of complex materials.
Article
Nanoscience & Nanotechnology
Mehrdad Abbasi, Yutao Dong, Jun Meng, Dane Morgan, Xudong Wang, Jinwoo Hwang
Summary: The evolution of medium range ordering (MRO) and crystallization behavior of amorphous TiO2 films grown by atomic layer deposition were investigated using in situ four-dimensional scanning transmission electron microscopy. The degree of MRO increases with temperature and reaches the maximum when crystallization starts to occur. In addition, post-annealing only develops a small portion of MRO into crystal nuclei, while the remaining MRO regions undergo structural relaxation. Crystallographic defects within crystal phases were observed, which may affect the corrosion resistance of the film. Understanding and controlling MRO is important for optimizing ALD-grown amorphous films for future functional devices and renewable energy applications.
Article
Engineering, Electrical & Electronic
Lin Lin, Ryan Jacobs, Dane Morgan, John Booske
Summary: Recent experiments on the perovskite oxide SrVO3 demonstrate the potential for achieving low work functions using surface dipoles on polar perovskites. Additional density functional theory calculations suggest that many other perovskites, including BaMoO3, may also exhibit low work function. In this study, the thermionic emission behavior of BaMoO3 was investigated, showing a temperature limited emission current density that increases and saturates with increasing voltage. The material exhibits an overall effective work function comparable to LaB6, but higher than the lowest work function predicted by DFT. The discrepancy is attributed to patch field effects caused by nanoscale features on individual surface facets. BaMoO3 also exhibits some instability at high temperatures, but shows comparable emission behavior to LaB6 at temperatures below 1200 degrees C, making it a potential vacuum electron source for applications such as electron microscopes and electron beam writers.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Dongzheng Chen, Ryan Jacobs, Dane Morgan, John Booske
Summary: In the study of thermionic electron emission, the shape of the Miram curve knee, which represents the transition between the exponential region and the saturated emission regions, plays a crucial role in evaluating the quality of thermionic vacuum cathodes. This research provides a comprehensive understanding of the physical factors, including the space charge effect and the patch field effect, that determine the shape of the knee. By using a model system with a periodic, equal-width striped work function distribution, the study illustrates how these physical effects restrict the emission current density near the Miram curve knee. The results identify three key physical parameters that significantly impact the shape of the Miram curve, providing new insights for the design of thermionic cathodes in vacuum electronic devices.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Materials Science, Multidisciplinary
Jianqi Xi, Yeqi Shi, Vitaly Pronskikh, Frederique Pellemoine, Dane Morgan, Izabela Szlufarska
Summary: Using atomistic simulations, we investigated the behavior of helium bubbles in beryllium, focusing on their shape, stability, and diffusivity. We found that helium bubbles become unstable and change shape through plastic deformation when the helium-vacancy ratio exceeds 1.25. The dominant diffusion mechanism of helium bubbles changes from surface diffusion to volume diffusion at around 900 K. The results provide valuable insights into the microstructural evolution and properties of irradiated materials.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Multidisciplinary Sciences
Yutao Dong, Mehrdad Abbasi, Jun Meng, Lazarus German, Corey Carlos, Jun Li, Ziyi Zhang, Dane Morgan, Jinwoo Hwang, Xudong Wang
Summary: Amorphous titanium dioxide (TiO2) film coating by atomic layer deposition (ALD) is a promising strategy to extend the photoelectrode lifetime for solar fuel generation. In this work, it is revealed that residual chlorine (Cl) ligands are detrimental to the silicon (Si) photoanode lifetime. Post-ALD in-situ water treatment effectively improves the film stoichiometry and preserves the amorphous phase, leading to a substantially improved lifetime for the protected Si photoanode.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Ryan Jacobs, Priyam Patki, Matthew J. Lynch, Steven Chen, Dane Morgan, Kevin G. Field
Summary: Accurate quantification of nanoscale cavities in irradiated alloys is achieved using the Mask R-CNN model, which provides insights into alloy performance and swelling metrics. The model demonstrates good performance in terms of statistical and materials property-centric evaluations, enabling accurate assessments of swelling in alloys.
SCIENTIFIC REPORTS
(2023)
Review
Physics, Applied
Lin Lin, Ryan Jacobs, Tianyu Ma, Dongzheng Chen, John Booske, Dane Morgan
Summary: In this review, the authors define different aspects of the work function and discuss the role of electric fields in work-function measurement and interpretation. They review standard experimental approaches and computational tools for measuring and predicting work function, and explore the influence of materials chemistry and structure on work-function trends. The authors also discuss the role of work function in various applications and provide guidance for engineering work-function values.
PHYSICAL REVIEW APPLIED
(2023)
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
Energy & Fuels
Xiu-Liang Lv, Patrick T. Sullivan, Wenjie Li, Hui-Chun Fu, Ryan Jacobs, Chih-Jung Chen, Dane Morgan, Song Jin, Dawei Feng
Summary: This study successfully synthesized an ionic liquid-mimicking catholyte for aqueous organic redox flow batteries (AORFBs) that demonstrated high performance in terms of stability, power, and energy density. The optimized catholyte showed robust cycling stability, high power density, and high energy density, paving the way for low-cost and scalable AORFBs.
Article
Chemistry, Multidisciplinary
Ziyi Zhang, Maciej P. Polak, Corey Carlos, Yutao Dong, Dane Morgan, Xudong Wang
Summary: Two-dimensional ferromagnetic materials with strong room-temperature ferromagnetism have been synthesized using an ionic layer epitaxy strategy. The ferromagnetic strength of the NiOOH nanosheets can be controlled by adjusting the surfactant monolayer density and annealing process, offering a promising pathway for achieving strong ferromagnetism in two-dimensional materials for spintronic applications.
Article
Materials Science, Multidisciplinary
Shipeng Shu, Yinbin Miao, Bei Ye, Kun Mo, Laura Jamison, Sumit Bhattacharya, Aaron Oaks, Abdellatif M. Yacout, Jason Harp, L. Amulya Nimmagadda, Sanjiv Sinha
Summary: This study investigates the thermal conductivity of U3Si2 that has been amorphized by ion irradiation. The results show that the thermal conductivity of amorphous U3Si2 is significantly lower than that of crystalline U3Si2, which is consistent with previous research findings.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Ryan Jacobs, Mingren Shen, Yuhan Liu, Wei Hao, Xiaoshan Li, Ruoyu He, Jacob R. C. Greaves, Donglin Wang, Zeming Xie, Zitong Huang, Chao Wang, Kevin G. Field, Dane Morgan
Summary: In this study, a deep learning model was used for quantitative analysis of multiple defect types in TEM images of irradiated FeCrAl alloys. The model's performance and limitations were evaluated, and useful evaluation tests were provided to understand its applicability. The model accurately predicted irradiation-induced material hardening and efforts are being made to develop an easy-to-use defect detection tool.
CELL REPORTS PHYSICAL SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Y. Liu, K. Zweiacker, C. Liu, J. T. McKeown, J. M. K. Wiezorek
Summary: The evolution of rapid solidification microstructure and solidification interface velocity of hypereutectic Al-20at.%Cu alloy after laser melting has been studied experimentally. It was found that the formation of microstructure was dominated by eutectic, alpha-cell, and banded morphology grains, and the growth modes changed with increasing interface velocity.
Article
Materials Science, Multidisciplinary
Bharat Gwalani, Julian Escobar, Miao Song, Jonova Thomas, Joshua Silverstein, Andrew Chihpin Chuang, Dileep Singh, Michael P. Brady, Yukinori Yamamoto, Thomas R. Watkins, Arun Devaraj
Summary: Castable alumina forming austenitic alloys exhibit superior creep life and oxidation resistance at high temperatures. This study reveals the mechanism behind the enhanced creep performance of these alloys by suppressing primary carbide formation and offers a promising alloy design strategy for high-temperature applications.
Article
Materials Science, Multidisciplinary
Jian Song, Qi Zhang, Songsong Yao, Kunming Yang, Houyu Ma, Jiamiao Ni, Boan Zhong, Yue Liu, Jian Wang, Tongxiang Fan
Summary: Recent studies have shown that achieving an atomically flat surface for metals can greatly improve their oxidation resistance and enhance their electronic-optical applications. Researchers have explored the use of graphene as a covering layer to achieve atomically flat surfaces. They found that high-temperature deposited graphene on copper surfaces formed mono-atomic steps, while annealed copper and transferred graphene on copper interfaces formed multi-atomic steps.
Article
Materials Science, Multidisciplinary
Jennifer A. Glerum, Jon-Erik Mogonye, David C. Dunand
Summary: Elemental powders of Al, Ti, Sc, and Zr are blended and processed via laser powder-bed fusion to create binary and ternary alloys. The microstructural analysis and mechanical testing show that the addition of Ti results in the formation of primary precipitates, while the addition of Sc and Zr leads to the formation of fine grain bands. The Al-0.25Ti-0.25Zr alloy exhibits comparable strain rates to Al-0.5Zr at low stresses, but significantly higher strain rates at higher stresses during compressive creep testing. Finite element modeling suggests that the connectivity of coarse and fine grain regions is a critical factor affecting the creep resistance of the alloys.
Article
Materials Science, Multidisciplinary
P. Jannotti, B. C. Hornbuckle, J. T. Lloyd, N. Lorenzo, M. Aniska, T. L. Luckenbaugh, A. J. Roberts, A. Giri, K. A. Darling
Summary: This work characterizes the thermo-mechanical behavior of bulk nanocrystalline Cu-Ta alloys under extreme conditions. The experiments reveal that the alloys exhibit unique mechanical properties, behaving differently from conventional nanocrystalline Cu. They do not undergo grain coarsening during extrusion and exhibit behavior similar to coarse-grained Cu.
Article
Materials Science, Multidisciplinary
Yiqing Wei, Jingwei Li, Daliang Zhang, Bin Zhang, Zizhen Zhou, Guang Han, Guoyu Wang, Carmelo Prestipino, Pierric Lemoine, Emmanuel Guilmeau, Xu Lu, Xiaoyuan Zhou
Summary: This study proposes a new strategy to modify microstructure by phase regulation, which can simultaneously enhance carrier mobility and reduce lattice thermal conductivity. The addition of Cu in layered SnSe2 induces a phase transition that leads to increased grain size and reduced stacking fault density, resulting in improved carrier mobility and lower lattice thermal conductivity.
Article
Materials Science, Multidisciplinary
Jia Chen, Zhengyu Zhang, Eitan Hershkovitz, Jonathan Poplawsky, Raja Shekar Bhupal Dandu, Chang-Yu Hung, Wenbo Wang, Yi Yao, Lin Li, Hongliang Xin, Honggyu Kim, Wenjun Cai
Summary: In this study, the structural origin of the pH-dependent repassivation mechanisms in multi-principal element alloys (MPEA) was investigated using surface characterization and computational simulations. It was found that selective oxidation in acidic to neutral solutions leads to enhanced nickel enrichment on the surface, resulting in reduced repassivation capability and corrosion resistance.
Article
Materials Science, Multidisciplinary
X. Y. Xu, C. P. Huang, H. Y. Wang, Y. Z. Li, M. X. Huang
Summary: The limited slip systems of magnesium (Mg) and its alloys hinder their wide applications. By conducting tensile straining experiments, researchers discovered a rate-dependent transition in the dislocation mechanisms of Mg alloys. At high strain rates, glissile dislocations dominate, while easy-glide dislocations dominate at low strain rates. Abundant glissile dislocations do not necessarily improve ductility.
Article
Materials Science, Multidisciplinary
M. S. Szczerba, M. J. Szczerba
Summary: Inverse temperature dependences of the detwinning stress were observed in face-centered cubic deformation twins in Cu-8at.%Al alloy. The detwinning stress increased with temperature when the pi detwinning mode was involved, but decreased when the pi/3 mode was involved. The dual effect of temperature on the detwinning stress was due to the reduction of internal stresses pre-existing within the deformation twins. The complete reduction of internal stresses at about 530 degrees C led to the equivalence of the critical stresses of different detwinning modes and a decrease in the yield stress anisotropy of the twin/matrix structure.
Article
Materials Science, Multidisciplinary
Taowen Dong, Tingting Qin, Wei Zhang, Yaowen Zhang, Zhuoran Feng, Yuxiang Gao, Zhongyu Pan, Zixiang Xia, Yan Wang, Chunming Yang, Peng Wang, Weitao Zheng
Summary: The interaction between the electrode and the electric double layer (EDL) significantly influences the energy storage mechanism. By studying the popular alpha-Fe2O3 electrode and the EDL interaction, we find that the energy storage mechanism of the electrode can be controlled by modulating the EDL.
Article
Materials Science, Multidisciplinary
Matthew R. Barnett, Jun Wang, Sitarama R. Kada, Alban de Vaucorbeil, Andrew Stevenson, Marc Fivel, Peter A. Lynch
Summary: The elastic-plastic transition in magnesium alloy Mg-4.5Zn exhibits bursts of deformation, which are characterized by sudden changes in grain orientation. These bursts occur in a coordinated manner among nearby grains, with the highest burst rate observed at the onset of full plasticity. The most significant burst events are associated with twinning, supported by the observation of twinned structures using electron microscopy. The bursts are often preceded and followed by a stasis in peak movement, indicating a certain "birth size" for twins upon formation and subsequent growth at a later stage.
Article
Materials Science, Multidisciplinary
Vaidehi Menon, Sambit Das, Vikram Gavini, Liang Qi
Summary: Understanding solute segregation thermodynamics is crucial for investigating grain boundary properties. The spectral approach and thermodynamic integration methods can be used to predict solute segregation behavior at grain boundaries and compare with experimental observations, thus aiding in alloy design and performance control.
Article
Materials Science, Multidisciplinary
Feiyu Qin, Lei Hu, Yingcai Zhu, Yuki Sakai, Shogo Kawaguchi, Akihiko Machida, Tetsu Watanuki, Yue-Wen Fang, Jun Sun, Xiangdong Ding, Masaki Azuma
Summary: This study reports on the negative and zero thermal expansion properties of Cd2Re2O7 and Cd1.95Ni0.05Re2O7 materials, along with their ultra-low thermal conductivity. Through investigations of their structures and phonon calculations, the synergistic effect of local structure distortion and soft phonons is revealed as the key to achieving these distinctive properties.
Article
Materials Science, Multidisciplinary
Thomas Beerli, Christian C. Roth, Dirk Mohr
Summary: A novel testing system for miniature specimens is designed to characterize the plastic response of materials for which conventional full-size specimens cannot be extracted. The system has an automated operation process, which reduces the damage to specimens caused by manual handling and improves the stability of the test results. The experiments show that the miniature specimens extracted from stainless steel and aluminum have high reproducibility, and the results are consistent with those of conventional-sized specimens. A correction procedure is provided to consider the influence of surface roughness and heat-affected zone caused by wire EDM.
Article
Materials Science, Multidisciplinary
Rani Mary Joy, Paulius Pobedinskas, Nina Baule, Shengyuan Bai, Daen Jannis, Nicolas Gauquelin, Marie-Amandine Pinault-Thaury, Francois Jomard, Kamatchi Jothiramalingam Sankaran, Rozita Rouzbahani, Fernando Lloret, Derese Desta, Jan D'Haen, Johan Verbeeck, Michael Frank Becker, Ken Haenen
Summary: This study investigates the influence of film microstructure and composition on the Young's modulus and residual stress in nanocrystalline diamond thin films. The results provide insights into the mechanical properties and intrinsic stress sources of these films, and demonstrate the potential for producing high-quality nanocrystalline diamond films under certain conditions.
