A5037249277- Advancements in Battery Materials
- Magnetic properties of thin films
- Electron and X-Ray Spectroscopy Techniques
- Advanced Battery Technologies Research
- Advanced Battery Materials and Technologies
- Nuclear Physics and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Magnetic Properties of Alloys
- Magnetic and transport properties of perovskites and related materials
- Magnetic Properties and Applications
- Advanced X-ray Imaging Techniques
- High-pressure geophysics and materials
- Radiation Shielding Materials Analysis
- Atomic and Subatomic Physics Research
- Rare-earth and actinide compounds
- Advanced Condensed Matter Physics
- Advanced X-ray and CT Imaging
- Semiconductor materials and devices
- Electronic and Structural Properties of Oxides
- Theoretical and Computational Physics
- Characterization and Applications of Magnetic Nanoparticles
- Extraction and Separation Processes
- Graphite, nuclear technology, radiation studies
- Advanced Chemical Physics Studies
- Thermal and Kinetic Analysis
Gunma University
2015-2024
Kiryu University
2012-2022
Carnegie Mellon University
2021
Northeastern University
2021
Helsinki Institute of Physics
2021
University of Helsinki
2021
Japan Synchrotron Radiation Research Institute
2021
SPring-8
2021
Lappeenranta-Lahti University of Technology
2021
University of Fukui
2018
Cobalt is used in Li-ion batteries, but it expensive and could be replaced by nickel to deliver better performance at a lower cost. With this motivation, we discuss how the character of redox orbitals LiNiO$_2$ can ascertained through x-ray Compton scattering measurements combined with parallel first-principles simulations. Our analysis reveals nature hole states Li-doped NiO resulting from hybridization O 2$p$ Ni 3$d$ orbitals. study also gives insight into ferromagnetic ground state...
We present an incisive spectroscopic technique for directly probing redox orbitals based on bulk electron momentum density measurements via high-resolution x-ray Compton scattering. Application of our method to spinel LixMn2O4, a lithium ion battery cathode material, is discussed. The orbital involved in the insertion and extraction process shown mainly be oxygen 2p orbital. Moreover, manganese 3d states are experience spatial delocalization involving 0.16 electrons per Mn site during...
Results of studies on Compton scattering imaging using synchrotron high-energy X-rays are reported. The technique is applied to a discharging coin cell, and the intensity scattered from inside cell has been measured as function position time. position–time map captures migration lithium ions in positive electrode reveals structural change due volume expansion electrode. This experiment critical step developing synchrotron-based for electrochemical cells at product level.
A spectroscopic descriptor of the link between lattice distortion and voltage in Li battery materials.
Orbital ordering below 30 K was previously observed in the ferromagnetic ${\text{YTiO}}_{3}$ compound both by polarized neutron diffraction (PND) and x-ray magnetic (XMD). In this paper we report a procedure for joint refinement of unique spin-density model based on PND XMD data. The distribution unpaired $3d$ electron titanium is clearly seen magnetization density reconstructed maximum entropy method from data collection at 5 K. ${\text{Ti}}^{3+}$ orbital populations obtained are discussed...
The performance of Li
Increasing electrode thickness is gaining more attention as a potential route to increase energy density for Li ion batteries although the realizable capacity and rate capability are usually limited by Li+ diffusion during (dis)charge, especially at increased (dis)charge rates. It remains challenging visualize quantify low atomic number chemical stoichiometry distribution inside within commercially standard battery geometry, e.g. coin cells with stainless steel casings. Here, we map of + in...
Compton scattering is one of the most promising probes for quantitating Li under in operando conditions, since high-energy X-rays, which have high penetration power, are used as incident beam and Compton-scattered energy spectrum has specific line-shapes each element. An quantitation method to determine composition electrodes been developed by using line-shape ( S -parameter) analysis spectrum. In this study, -parameter applied a commercial coin cell Li-ion rechargeable battery variation...
Non-destructive determination of lithium distribution in a working battery is key for addressing both efficiency and safety issues. Although various techniques have been developed to map the electrodes, these methods are mostly applicable test cells. Here, we propose use high-energy x-ray Compton scattering spectroscopy measure local concentration closed electrochemical A combination experimental measurements parallel first-principles computations used show that shape parameter S profile...
High-energy synchrotron X-ray Compton scattering imaging was applied to a commercial 18650-type cell, which is cylindrical lithium-ion battery in wide current use. By measuring the energy spectrum non-destructively, lithiation state both fresh and aged cells obtained from two different regions of one near outer casing other center cell. Our technique has advantage that it can reveal with micron-scale spatial resolution even large cells. The present method enables us monitor operation...
Spinel Li$_x$Mn$_2$O$_4$ is a key cathode material that used extensively in commercial Li-ion batteries. A challenge with this has been the capacity of battery fades cycling, an effect can be traced to presence anti-ferromagnetic insulator phase fully lithiated LiMn$_2$O$_4$ (LMO) and associated charge disproportionation drives distortions MnO$_6$ octahedra. Here, by combining x-ray magnetic Compton scattering experiments parallel first-principles computations, we show LMO surrounded robust...
In this study, lithium reaction distributions, dependent on the charge–discharge rate, were non-destructively visualized for a commercial lithium-ion battery, using Compton scattering imaging technique. By comparing distributions obtained at two different speeds, residual ions detected center of negative electrode in fully discharged state, relatively high-speed discharge rate. Moreover, we confirmed that inhomogeneous reactions facilitated both and positive electrodes. A feature our...
We discuss how x-ray Compton scattering spectra can be used for investigating the evolution of electronic states in cathode materials Li batteries under lithiation/delithiation process. In particular, our analysis taken from polycrystalline LixCoO2 samples shows that are dominated by contribution O-2p redox orbital. identify a distinct signature d-orbital delocalization, which is tied directly to conductivity material, providing descriptor based on monitoring lithiation range with improved...
In the through silicon via (TSV) structure for 3-dimentional integration (3DI), large thermal-mechanical stress acts in BEOL layer caused by mismatch thermal expansion coefficient (CTE) of TSV materials. The resulting high-stress region is thought to be critical point initiation cracking or de-lamination that affects mechanical reliability. this study, multi-stacked thin Si wafers composed copper and copper/low-k was analyzed finite element method (FEM), aiming reduce LSI devices 3D-IC....
An experimental system of X-ray magnetic diffraction (XMD) for ferromagents is established at the Photon Factory in KEK to realize high photon-counting rate up 105 cps and magnetic-field strength over 20 kOe. These performances have been achieved by upgrading (i) an detector apparatus (ii) electromagnet, respectively. The spin form factor ferromagnetic YTiO3 30 reciprocal lattice points hk0 0kl series has measured using XMD various geometries including direction parallel hard axis. result...
The fabrication of WOW (wafer-on-a-wafer) with MEMS technology has been developed. A wafer was thinned and stacked on a base wafer. After the TSVs were patterned wafer, they filled by Cu for interconnection. wafers bonded benzocylcobutene (BCB, CYCLOTENE <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TM</sup> ) as an adhesive material. BCB layer also acted dielectric between top bottom silicon wafers. created DRIE (deep reactive ion etching)...
We compare two Co/Pd multilayers with correspondingly smooth and rough interfaces. The first is a Co (1.5 nm)/Pd (2.6 nm) multilayer interface deposited by the MBE technique, second (1.6 (4.0 sputter technique. Both have almost same perpendicular magnetic anisotropy energy, 1.15 Merg/cc for 1.20 multilayer, respectively. symmetry of wave function, which measured using Compton profile, both multilayers. This suggests that controls function enhances PMA energy even if has thinner Pd layer.
Electron concentration in highly resistive GaN substrates with intentional iron (Fe) dopants as well unintentionally incorporated silicon (Si) and carbon (C) has been investigated. Si, C, Fe atomic concentrations were 2 × 1017, 1 1016, 1019 cm−3, respectively measured by secondary ion mass spectroscopy (SIMS). Temperature dependence of current–voltage (I–V) characteristics revealed that the resistivity (ρ) was 3.8 109 Ω cm at 300 K monotonously decreased to 3.1 104 570 K, giving an...
High energy X-rays (115.56 keV) were used to measure the HIPed interface of F82H steel. The X-ray spectra samples analyzed focusing on W and Ta fluorescence X-rays, Compton scattering elastic X-rays. results suggest presence SiOx TaOx at HIP accumulation near interface. These indicate that high-energy spectrum analysis can be a non-destructive testing technique (NDT) evaluate precipitates