【提出用】

Electron Microscopy, Theoretical Calculation, Data Science, Machine Learning

Fe312

0 LMIZOGUCHI] R J X F K L LAB.
/$%Understanding※ 研 究 室Materials
名 の み 入through力 く だ Microscopy,
さいComputation, and Machine Learning
Department of Materials and Environmental Science
Nano-Materials Design
Department of Materials Engineering, Graduate School of Engineering

1Materials Design

What kind of Structures?
How to bring about the Properties

Property

Structure

Relationship
Paving the way
NMDL

https://www.edge.iis.u-tokyo.ac.jp/～Paving the Way for Materials Design～

Property-Structure Relationship for Materials Design
Much higher performance and higher reliability
are now required to the materials to achieve
further technology developments. In case ofelectroceramics, such as multi-layer ceramic
capacitor and varistor, the size of grains indevices becomes smaller and smaller, andfurther property improvements of each grain
and grain boundary are desired. To achieve this,clarification of atomic and electronic structuresand finding the way to improve their properties
are indispensable.

In our group, atomic and electronic structure areinvestigated by combining electron energy loss
spectroscopy (EELS), transmission electron
microscopy (TEM), first principles calculation. By
combining these methods, atomic and electronicstructures and their relationships with materials
properties can be unraveled.
Particularly, superlattice, ionic liquid, Li-ion
battery, photovoltaic cell, electroceramics, andglass are investigated.

2 Seeing Atoms & Bonding
Atomic resolution analysisof glass

Analysis of energy materials$XDWRPVLQOLTXLG

6RODUFHOOPDWHULDO(U DWRPLQ2SWLFDOJODVVILEHU

Atomic resolution analysis
of liquid
9RURQRL GLDJUDP

Analysis of thermal expansion
at grain boundaries

Single, Excitonic, Multiplet in ELNES

SrTiO3
Σ5Ground state

QP/LLRQEDWWHU\(UQP

Analysis ofglass phase separation

We are investigating electron-energy-loss near-edge
structures (ELNES) and X-ray absorption near-edge
structures (XANES) from experimental and theoretical
viewpoints. ELNES and XANES originate from theelectron transition from a core orbital to unoccupiedbands. Their spectral features reflect the partial densityof states of unoccupied bands, which contains
information on the atomic and electronic structures.
Experimentally, spatial- and time- resolved ELNES canbe obtained at high accuracy by STEM-EELS.
On the other hand, theoretical calculation is necessary
to interpret the experimental spectrum. Including effectof core-hole, which is introduced by electron transition
from core-orbital to conduction band, is indispensable
to calculate spectrum structures correctly.

Li2.00Mn03
Li1.50Mn03
Li1.00Mn03

640

Excitonic interaction in ELNESQPCA([SB645650
Energy /eV4+3D dynamics of liquid

Li2.00MnO3(Mn 660)
655
4+

Li1.50MnO3(Mn )4+Normarized Absorption /a.u.

Core-hole@Mg 1s0Q/ (/1(6B

Normarized Absorption /a.u.

Core-hole@Oxygen 1s

Li1.00MnO3(Mn )CK. Nakazawa et al. Phys. Rev. Res. 4, (2022) 033052; K. Liao et al., Nano Lett. 21 (2021) 10416-10422; K.
Nakazawa et al., Ultramicroscopy, 217 (2020) 113077-1-8; K. Liao et al., ACS Applied Nano Mater. (2020); Y.
Sugimori et al., RSC Advances, 9 (2019) 10520; K. Nakazawa et al., Scripta Mater. 154 (2018) 197; T. Miyataet al., Science Adv. 3 (2017) e1701546; T. Miyata et al., Ultram. 178 (2017) 81; T. Miyata et al., Microscopy
3 (2014) 377; H. Katsukura et al., Sci. Rep. 7 (2017) 16434; K. Tomita et al., Ultram. 178 (2017) 105-111; K.
Tomita et al., J.Phys. Chem. C 120 (2016) 9036-9042; Y. Matsui et al., Chem. Phys. Lett. 649 (2016) 92; Y.
Matsui, Sci. Rep. 3 (2013) 3503-1-7; K. Kubobuchi et al., Appl. Phys. Lett. 104 (2014) 053906; T. Mizoguchiet al., ACS Nano 7 (2013) 5058; S. Ootsuki et al., Appl. Phys. Lett. 99 (2011) 233109.

A&DOF
640645650
Energy /eV655

660

3 Understanding the Role of Atoms and Electrons in Materials
Core-loss spectra database

Structure from core-loss spectra

Properties from core-loss spectra

Prediction of gain boundary properties

Development of fast method to determineinterface structure

Electronic structure from core-loss spectra

To design materials properties, we are investigating atomic and electronic structures quantitatively by performing high-precision
simulations of atomic structures such as interfaces and lattice defects, which have a great impact on the functions of materials, and coreexcitation spectra, which show a variety of shapes reflecting electronic states. In addition, from the viewpoint of materials informatics,
where information science is used for materials research, we are working on the creation of a large and systematic database of coreexcitation spectra and interfaces, and on the prediction and understanding of structure-function relationships by utilizing various
machine learning methods.

PY. Chen et al., J. Phys. Chem. Lett. 14 (2023) 4858; Y. Hata et al., J. Ceram. Soc. Jpn., 131 (2023) 738; YS. Xie et al.
Comp. Phys. Comm. 273 (2022) 108260-1-8; K. Shibata et al., Sci. Data 9 (2022) 214 ; E. Suzuki et al., Appl. Phys.
Express 14 (2021) 085503; K. Kikumasa et al., Adv. Intell. Syst., 4 (2022) 2100103-1-10; S. Kiyohara and T.
Mizoguchi, J. Phys. Soc. Jpn. 89 (2020) 103001;S. Kiyohara et al., npj Comp. Mater. 6 (2020) 68; R. Otani et al.,Appl. Phys. Express 13 (2020) 065504; S. Kiyohara et al., J. Phys: Mater. 2 (2019) 024003; M. Tsubaki et al., J. Phys.
Chem. Lett. 9 (2018) 5733; S. Kiyohara et al., Sci. Rep. 8 (2018) 13548; S. Kiyohara et al., J. Chem. Phys. 148 (2018)241741; H. Oda et al., J. Phys. Soc. Jpn 86 (2017) 123601; S. Kikuchi et al., Physica B 532 (2018) 9; S. Kiyohara etal., Physica B 532 (2018) 24; S. Kiyohara et al., Sci. Adv. 2 (2017) e1600746; S. Kiyohara et al., Jpn. J. Appl. Phys.
55 (2016) 045502-1-4; S. Kawanishi and T. Mizoguchi, J. Appl. Phys. 119 (2016) 175101; T. Yamamoto et al., Appl.
Phys. Lett. 105 (2014) 201604; H. Yamaguchi et al., J. Ceram. Soc. Jpn. 122 (2014) 469; H. Yamaguchi et al., Appl.
Phys. Lett. 104 (2014) 153904; T. Yamamoto et al., Appl. Phys. Lett. 102 (2013) 211910; T. Yamamoto et al., Phys.
Rev. B 86 (2012) 094117; T. Mizoguchi et al., Adv. Func. Mater. 21 (2011) 2258.