A5072813677- Microstructure and mechanical properties
- Catalytic Processes in Materials Science
- Graphene research and applications
- Electronic and Structural Properties of Oxides
- Copper-based nanomaterials and applications
- Catalysis and Oxidation Reactions
- Advancements in Battery Materials
- Supercapacitor Materials and Fabrication
- ZnO doping and properties
- Surface and Thin Film Phenomena
- Ferroelectric and Piezoelectric Materials
- Quasicrystal Structures and Properties
- Quantum Dots Synthesis And Properties
- Metal Forming Simulation Techniques
- X-ray Diffraction in Crystallography
- Metallurgy and Material Forming
- Magnetic and transport properties of perovskites and related materials
- Magnetic Properties and Synthesis of Ferrites
- Magnetic properties of thin films
- Semiconductor materials and devices
- Acoustic Wave Resonator Technologies
- 2D Materials and Applications
- Conducting polymers and applications
- Advanced Electron Microscopy Techniques and Applications
- Advanced Battery Materials and Technologies
Tohoku University
2016-2025
Advanced Institute of Materials Science
2018-2025
Japan Science and Technology Agency
2019-2021
Sendai University
2021
Institute for Materials Research, Tohoku University
2020
The University of Tokyo
2017-2018
TDK (Japan)
2002
Glenn Research Center
1993
Atomic-scale analysis of the cation valence state distribution will help to understand intrinsic features oxygen vacancies (VO ) inside metal oxide nanocrystals, which, however, remains a great challenge. In this work, cerium states across ultrafine CeO2 nanocubes (NCs) perpendicular {100} exposed facet is investigated layer-by-layer using state-of-the-art scanning transmission electron microscopy-electron energy loss spectroscopy. The effect size on Ce NCs demonstrated as changed from 11.8...
The rational design of a stable and catalytic carbon cathode is crucial for the development rechargeable lithium-oxygen (LiO
In the fundamental understanding of magnetic interactions between atoms in solids, crystal lattice is one key parameters.As effective tool for controlling using tensile stress limited, there are only few demonstrations control properties with expanding structure.Here, we observe that Curie temperature (Tc) quasi two-dimensional Cr2Ge2Te6 NiO overlayer doubles from ~60 K to ~120 K, describe a clear correlation expansion, which characterized by several probes and computational approaches,...
Clarifying how the atomic structure of interfaces/boundaries in materials affects magnetic coupling nature across them is significant academic value and will facilitate development state-of-the-art devices. Here, by combining atomic-resolution transmission electron microscopy, atomistic spin-polarized first-principles calculations, differential phase contrast imaging, we conduct a systematic investigation electronic structures individual Fe3O4 twin boundaries (TBs) determine their...
Although the function and stability of catalysts are known to significantly depend on their dispersion state support interactions, mechanism catalyst loading has not yet been elucidated. To address this gap in knowledge, study elucidates Pt based a detailed investigation interaction between species localized polarons (Ce3+) associated with oxygen vacancies CeO2(100) facets. Furthermore, an effective method was proposed for achieving high catalytic activity while maintaining stability....
The temperature dependence of magnetocrystalline anisotropy constants and the saturation magnetization in a single variant state have been investigated for L10-type Fe60Pt40 bulk crystal prepared under compressive stress. uniaxial constant Ku evaluated from curve is 6.9×107ergcm−3 at 5K. values second- fourth-order K1 K2 5K determined by Sucksmith–Thompson method are 7.4 0.13×107ergcm−3, respectively. Both decrease with increasing T, while almost independent T. difference between power law...
A global optimization procedure is used to predict the structure and electronic properties of b = c[001] edge dislocation in rutile TiO2. Over 1000 different atomic configurations have been generated using both semi-empirical density functional theory estimates energy system identify most stable structure. Both stoichiometric oxygen deficient core structures are predicted be depending on chemical potential. The latter associated with Ti3+ species core. act as a trap for electrons but not...
Abstract Organic surfactant controls the synthesis of nanocrystals (NCs) with uniform size and morphology by attaching on surface NCs further facilitates their assembly into ordered superstructure, which produces versatile functional nanomaterials for practical applications. It is essential to directly resolve molecules improve understanding chemistry NCs. However, imaging resolution contrast are insufficient a single molecule organic In this work, direct characterization CeO 2 conducted...
Chirality-controlled synthesis of carbon nanotubes (CNTs) is one the ultimate goals in field nanotube synthesis. At present, direct achieving a purity over 90%, which can be called single-chirality synthesis, has been achieved for only two types chiralities: (14,4) and (12,6) CNTs. Here, we realized an ultrahigh-purity (∼95.8%) (6,5) CNTs with trimetallic catalyst NiSnFe. Partial formation Ni
Abstract A twist in bi- or few-layer graphene breaks the local symmetry, introducing a number of intriguing physical properties such as opening new bandgaps. Therefore, determining twisted atomic structure is critical to understanding and controlling functional graphene. Combining low-angle annular dark-field electron microscopy with image simulations, we directly determine terms moiré superstructure which parameterized by single angle lattice constant. This method shown be powerful tool for...
Controlling the crystal structure of ferroelectric materials via epitaxial strain, which is a well-known technique in strain engineering, can lead to formation unique domain structures generating non-intrinsic phenomena such as electronic conductivity, photovoltages, and enhanced piezoelectric characteristics. Strained BaTiO3 films are promising theoretical modeling predicts that different morphologies introduce additional properties not observed conventional ceramics. To rationally design...
The formation of nanoscale phases at grain boundaries in polycrystalline materials has attracted much attention, since it offers a route toward targeted and controlled design interface properties. However, understanding structure–property relationships these complex interfacial defects is hampered by the great challenge accurately determining their atomic structure. Here, we combine advanced electron microscopy together with ab initio random structure searching to determine an experimentally...
Abstract Porous carbons are important electrode materials for supercapacitors. One of the challenges associated with supercapacitors is improving their energy density without relying on pseudocapacitance, which based fast redox reactions that often shorten device lifetimes. A possible solution involves achieving high total capacitance ( C tot ), comprises Helmholtz H ) and possibly quantum Q in high‐surface carbon comprising minimally stacked graphene walls. In this work, a templating method...
A collaborative work between mathematics and atom-resolved scanning transmission electron microscopy (STEM) has been conducted. The grain boundary in a bicrystal of simple rock-salt oxide can show complicated arrangement structural units, which be well predicted by an algorithm utilizing the Farey sequence. estimated arrangements had nice agreement with those observed STEM atomic-scale up to several tens nanometers.
Surfactant-mediated morphology evolution of CeO<sub>2</sub> nanocrystals is fully investigated at the atomic scale and it was found that exposure {100} facets largely affects concentration Ce<sup>3+</sup> subsequently OSC performance.
We report an application of the O-lattice theory to systematically analyse structures symmetrical tilt grain boundaries with rotation axis 〈001〉 and demonstrate a theoretical interpretation experimentally observed near Σ5 boundary in MgO terms structural-units model periodicity O-points on boundary. further derive generalised decomposition formulae for which are closely related distribution irreducible rational numbers.
A computer program was developed for designing a low vibration gearbox. The code is based on finite element shell analysis, modal and structural optimization method. In the triangular with 18 degrees-of-freedom used. method, overall energy of gearbox used as objective function minimized at exciting frequency by varying thickness. Modal analysis to derive sensitivity respect design variable. representative both eigenvalues eigenvectors. optimum value computed gradient projection method...
The quasi-one-dimensional (1D) metallic conductivity of the perovskite-related SrnNbnO3n+2 compounds is continuing fundamental physical interest as well being important for developing advanced electronic devices. can be derived by introducing additional oxygen into SrNbO3 perovskite. However, origin transition electrical properties from three-dimensional (3D) isotropic in to quasi-1D requires more in-depth clarification. Here we combine transmission electron microscopy with atomistic...
The general decomposition formula was established for the structures of symmetrical tilt grain boundaries with axis 〈001〉. By investigating underlying mathematical structure, we propose a novel algorithm to obtain arrangement structural units any misorientation angle boundary an arbitrary precision due Farey sequence.