Article
Engineering, Mechanical
Yukichika Hashizume, Masahiro Inomoto, Norihiko L. Okamoto, Haruyuki Inui
Summary: The plastic deformation behavior of single crystals of delta(1p) and delta(1k) phase compounds in the Fe-Zn system, which are major constituent phases in galvannealed (GA) steels, was investigated by micropillar compression tests. Different slip systems were observed in the delta(1p) and delta(1k) phase compounds, with strain bursts and instantaneous 'slip plane failure' occurring. The critical resolved shear stress (CRSS) for basal and prism slip showed inverse power-law scaling against specimen size.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Chemistry, Physical
Shuo Zhang, Gediminas Gervinskas, Yang Liu, Ross K. W. Marceau, Jing Fu
Summary: This study explores the application of nanoscale in-situ cryo-condensation coating technique on needle-shaped specimens and frozen hydrated cells. By controlling parameters, the properties of the deposited layer can be tuned, revealing surface morphologies and investigating the physical mechanisms of curing. This approach opens a novel route to nanofabrication on tip geometry and site-specific conductive protection.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Liangliang Gu, Han Gao, Haifeng Hu
Summary: We present a simple and robust fiber specklegram refractive index sensor using a multimode fiber-single mode fiber-multimode fiber structure based on focused ion beam milling. Fluid channels are etched on the single-mode fiber to enhance the interaction between light and matter, and a deep learning model is employed for demodulating the sensing signal. Experimental results demonstrate high demodulation accuracy and speed, making it a promising sensing scheme for various chemical and biological applications.
Article
Chemistry, Physical
Chiu-Yen Wang, An-Hsuan Hsu, Yi-Chen Lin, Ya-Chu Hsu
Summary: Monocrystalline InSe nanowires with a [100] growth direction were successfully prepared via vacuum hydraulic pressure injection at low temperature. The fabricated nanowires were used to create a high-responsivity photodetector with low dark current and rapid rise and fall times.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Rong Wu, M. Tauhiduzzaman, P. Ravi Selvaganapathy
Summary: Recently, there has been a growing interest in methods for creating hydrophobic surfaces, with a low-cost, high-throughput Computer Numerical Control machining method being developed to generate highly hydrophobic and anisotropic surfaces on both metal and polymeric materials. This method, utilizing micro-structured diamond tools, offers at least four times higher machining speed compared to other methods and demonstrates significant anisotropic wetting effects on the machined surfaces.
MATERIALS & DESIGN
(2021)
Article
Materials Science, Multidisciplinary
Mehrdad T. Kiani, Lucia T. Gan, Rachel Traylor, Rui Yang, Christopher M. Barr, Khalid Hattar, Jonathan A. Fan, X. Wendy Gu
Summary: Grain boundaries in metals and alloys have complex structural features that affect their mechanical behavior. This study used bicrystal Au thin films to investigate deformation at a single grain boundary and found that the misorientation angle of the grain boundary has minimal influence.
Article
Chemistry, Analytical
Michael Haub, Martin Bogner, Thomas Guenther, Andre Zimmermann, Hermann Sandmaier
Summary: This paper introduces a miniaturized accelerometer based on the tunneling effect, which utilizes high sensitivity to detect small deflections in the sub-nanometer range. The spring-mass system is manufactured through surface micro-machining, allowing control over the size of sensor structures and electrode distances. The exponential dependency of sensitivity on electrode distance affects the sensor signal, with a measuring range of 20 g.
Article
Materials Science, Multidisciplinary
Andrii Dubinko, Chao Yin, Dmitry Terentyev, Aleksandr Zinovev, Michael Rieth, Steffen Antusch, Monika Vilemova, Jiri Matejicek, Tao Zhang
Summary: The mechanical properties of various tungsten grades for applications in a nuclear fusion environment were assessed in this study. The research focused on bending tests, microstructural analysis, and TEM observation of different tungsten-based materials at 600 degrees C. The obtained data will be crucial for assessing the impact of neutron irradiation on the materials.
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Oleksandr Buchnev, James A. Grant-Jacob, Robert W. Eason, Nikolay I. Zheludev, Ben Mills, Kevin F. MacDonald
Summary: Researchers have developed a deep learning method based on prior experience to predict the postfabrication appearance of structures manufactured by focused ion beam (FIB) milling, which can expedite the optimization process and improve reproducibility in FIB processing.
Article
Materials Science, Multidisciplinary
Arijit Lodh, Clement Keller, Gustavo M. Castelluccio
Summary: This paper presents a simple method for manufacturing and testing dog-bone specimens with a minimum width of 50 μm. The study shows that sample size has a pronounced effect on the mechanical response of the materials, emphasizing the importance of further characterizing mesoscale samples. Additionally, the capability of testing the tensile response of single crystals from engineering alloys is demonstrated.
Article
Chemistry, Physical
Deying Xia, Ying-Bing Jiang, John Notte, Doug Runt
Summary: This study compares the usage of a neon focused ion beam with the traditional gallium focused ion beam for milling GaAs material, finding that neon FIB produces less undesired artifacts and subsurface damage at lower energies. Additionally, neon FIB can create trenches as small as 20 nm wide with high fidelity and minimal damage.
APPLIED SURFACE SCIENCE
(2021)
Article
Engineering, Electrical & Electronic
Shengxiao Jin, Ling Xia, Yifei Mao, Xiaoyu Chen, Zhuojie Chen, Can Li, Wengang Wu, Jun Xu
Summary: Focused ion beam (FIB) with keV Ga+ can introduce nanoscale localized tensile stress in various materials, which is utilized to assemble 2D nano-film patterns into 3D structures. A strained-bilayer-system model is proposed to describe the bending angle of the patterns. By applying proper stress-introducing strategy, a 3D cubic frame and helices are fabricated using FIB stress induced deformation (FIB-SID) technology. A programmable quasi-parallel FIB fabrication method is developed for efficient and consistent fabrication of 3D nanostructures.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Chemistry, Multidisciplinary
Qi-Meng Sun, Jing-Jing Xu, Fei-Fei Tao, Wen Ye, Chang Zhou, Jing-Hui He, Jian-Mei Lu
Summary: This study successfully synthesizes halide perovskite-based photocatalysts with efficient CO2 reduction performance in mesoporous TiO2 frameworks, and directly observes the nanoscale perovskite dots using ion-beam sliced imaging techniques. The mechanism behind the high methane selectivity is revealed through experiments and calculations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Yanran Liu, Yuanyuan Qu, Yue Liu, Hang Yin, Jinglun Liu, Yang Tan, Feng Chen
Summary: This study demonstrates the construction of lateral diodes on graphene-based heterostructures using focused ion-beam writing, achieving rectification and current regulating functions. The introduction of Se-defects endows the heterostructure with unique electronic properties, enabling the construction of diodes with comparable performance. Additionally, AND and OR logic gates were directly inscribed on the heterostructure to showcase practical applications in digital logic electronics.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Metallurgy & Metallurgical Engineering
Yan-qiu ZHANG, Shu-yong JIANG
Summary: Through MD simulation, it was found that nanotwinned polycrystalline copper with {111} texture exhibits hard and soft orientations during tensile deformation, each involving distinct dislocation mechanisms. The strengthening mechanism of hard orientation is attributed to interactions between dislocations and twin boundaries, while the softening mechanism of soft orientation is due to the lack of interaction between dislocations and twin boundaries.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2021)
Article
Engineering, Mechanical
Yukichika Hashizume, Masahiro Inomoto, Norihiko L. Okamoto, Haruyuki Inui
Summary: The plastic deformation behavior of single crystals of delta(1p) and delta(1k) phase compounds in the Fe-Zn system, which are major constituent phases in galvannealed (GA) steels, was investigated by micropillar compression tests. Different slip systems were observed in the delta(1p) and delta(1k) phase compounds, with strain bursts and instantaneous 'slip plane failure' occurring. The critical resolved shear stress (CRSS) for basal and prism slip showed inverse power-law scaling against specimen size.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Chemistry, Physical
Zhenghao Chen, Norihiko L. Okamoto, Kazuyoshi Chikugo, Haruyuki Inui
Summary: The effects of adding gamma' (L1(2))-forming elements and gamma (FCC)-forming elements on the microstructural stability, oxidation resistance, and creep properties of Co-based superalloys were investigated. A candidate composition with high gamma' solvus temperature and y' volume fraction was found to have superior oxidation resistance but only comparable creep properties to Ni-based superalloys of the first generation. Further research is needed to achieve both sufficient oxidation resistance and creep properties simultaneously for Co-based superalloys.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Marino Kawamura, Makoto Asakura, Norihiko L. Okamoto, Kyosuke Kishida, Haruyuki Inui, Easo P. George
Summary: The plastic deformation behavior of single crystals of the Cr-Mn-Fe-Co-Ni high-entropy alloy has been studied at different temperatures, showing sensitivity to strain rate, temperature, and crystal orientation. Solid-solution hardening is identified as the main strengthening mechanism, with deformation twinning occurring at low temperatures, impacting the material's tensile properties.
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
Bhaskar Paul, Norihiko L. Okamoto, Misato Kusakari, Zhenghao Chen, Kyosuke Kishida, Haruyuki Inui, Shigeki Otani
Summary: The plastic deformation behavior of single crystals of three transition-metal diborides, CrB2, TiB2 and ZrB2, was investigated at different temperatures, showing differences in plastic flow behavior influenced by crystal orientation and critical resolved shear stress.
Article
Chemistry, Physical
Takuya Hatakeyama, Hongyi Li, Norihiko L. Okamoto, Kohei Shimokawa, Tomoya Kawaguchi, Hiroshi Tanimura, Susumu Imashuku, Maximilian Fichtner, Tetsu Ichitsubo
Summary: The study revealed that under conditions where the magnesium migration kinetics are sufficiently enhanced, MnO2 polymorphs can transform into Mg-including spinels and then rocksalt-like phases. Alpha-MnO2 was found to exhibit reversible magnesium intercalation at 150 degrees C, while lambda-MnO2 phase possessing spinel/rocksalt structure framework is thermally unstable.
CHEMISTRY OF MATERIALS
(2021)
Article
Multidisciplinary Sciences
Zhenghao Chen, Bhaskar Paul, Sanjib Majumdar, Norihiko L. Okamoto, Kyosuke Kishida, Haruyuki Inui, Shigeki Otani
Summary: The plastic deformation behavior of single crystals of ZrB2 and TiB2 at room temperature was investigated using micropillar compression tests, which revealed that plastic flow can be observed through specific slip systems with high critical resolve shear stress values.
SCIENTIFIC REPORTS
(2021)
Article
Materials Science, Multidisciplinary
Daixiu Wei, Liqiang Wang, Yongjie Zhang, Wu Gong, Tomohito Tsuru, Ivan Lobzenko, Jing Jiang, Stefanus Harjo, Takuro Kawasaki, Jae Wung Bae, Wenjun Lu, Zhen Lu, Yuichiro Hayasaka, Takanori Kiguchi, Norihiko L. Okamoto, Tetsu Ichitsubo, Hyoung Seop Kim, Tadashi Furuhara, Evan Ma, Hidemi Kato
Summary: Recently-developed high-entropy alloys (HEAs) have expanded the compositional space and mechanical properties by substituting the constituent metals with metalloids. Metalloid substitution increases strength by increasing local lattice distortion and short-range chemical inhomogeneities, while reducing stacking fault energy to discourage dynamic recovery.
Article
Chemistry, Inorganic & Nuclear
Takuya Hatakeyama, Norihiko L. Okamoto, Tetsu Ichitsubo
Summary: This study investigates the thermal stability of alpha, beta, gamma, delta, and lambda-type MnO2 polymorphs using DSC and HTXRD. Results show that the thermal stability order of the polymorphs is beta > alpha > gamma > delta approximate to lambda. The structure and phase transformations of each phase under high temperature conditions are discussed in relation to the bonding environment of oxide ions.
JOURNAL OF SOLID STATE CHEMISTRY
(2022)
Article
Multidisciplinary Sciences
Takuya Hatakeyama, Norihiko L. Okamoto, Satoshi Otake, Hiroaki Sato, Hongyi Li, Tetsu Ichitsubo
Summary: This study demonstrates that birnessite-type layered manganese dioxide with crystal water can serve as a well-balanced heat storage material due to its water-intercalation mechanism, high energy density, and validated driving force for intercalation, providing an optimal solution for low-grade waste-heat applications.
NATURE COMMUNICATIONS
(2022)
Article
Nanoscience & Nanotechnology
Xiatong Ye, Hongyi Li, Takuya Hatakeyama, Hiroaki Kobayashi, Toshihiko Mandai, Norihiko L. Okamoto, Tetsu Ichitsubo
Summary: Rechargeable magnesium batteries are promising candidates for future batteries due to their abundant resources and high energy density. This study compares the reaction behavior of different MnO2 cathodes in two electrolytes and highlights the importance of interfacial stability for practical applications.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Robert Josef Enzinger, Martin Luckabauer, Norihiko L. Okamoto, Tetsu Ichitsubo, Wolfgang Sprengel, Roland Wurschum
Summary: A detailed understanding of the kinetics of phase formation in fi-stabilised titanium is crucial for their applicability, but specialized measurement techniques are needed due to the complex nature and long timescales of the transformations. High-stability isothermal laser dilatometry was used to study the volume changes of Ti-21 at. pct V samples during phase formation. Different behaviors were observed between samples with different solute oxygen content, and the temperature ranges for diffusionless and diffusion-assisted isothermal w-formation as well as w-to-a transformation were determined. The results confirm recent findings on the distinction between diffusionless and diffusion-assisted isothermal w formation modes. Modelling of w-phase formation using Austin-Rickett kinetics revealed temperature-dependent formation rates, which were used to develop isothermal TTT-diagrams reflecting the strong influence of oxygen content.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Multidisciplinary Sciences
Kaoru Okamoto Yoshiyama, Norihiko L. Okamoto, Jun Hidema, Atsushi Higashitani
Summary: Far-ultraviolet radiation C light (far-UVC; 222 nm wavelength) has been considered as a safer light for killing pathogenic bacteria and viruses, but its effectiveness and potential biological damage compared to 254-UVC (254 nm wavelength) were unclear. This study found that 222-UVC caused slightly less DNA damage but had a significant effect on motility loss and severe damage to the sensory nervous system in a model organism, Caenorhabditis elegans. In contrast, 254-UVC had a higher impact on survival of eggs and chromosomal condensation. These results suggest that 222-UVC is less penetrating but causes more severe damage in tissues near the surface.
Article
Chemistry, Physical
Norihiko L. Okamoto, Hiroki Yoshisako, Tetsu Ichitsubo
Summary: Layered manganese dioxide with K cations and water molecules shows reversible heat storage properties, but the initial irreversible capacity of water intercalation limits the energy density for subsequent cycles. This study analyzes the crystal structures of K-containing birnessite before and after heat treatment to understand the origin of the initial irreversible capacity. The analysis reveals that the ordered arrangement of K cations after heat treatment hinders the re-intercalation of excess water in subsequent cycles.
ENERGY STORAGE MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Hiroshi Tanimura, Norihiko L. Okamoto, Takao Homma, Yusuke Sato, Akihiro Ishii, Hitoshi Takamura, Tetsu Ichitsubo
Summary: This study investigates the ultrafast optical response of VTe2 and reveals the photoinduced phase transition process. It suggests that the high-temperature phase of VTe2 is induced within a picosecond through purely electronic effect and the phase transition dynamics proceed inhomogeneously via a nucleation mode.