Image gallery

2024

Effect of Strain Fields on the Formation of Oxygen Vacancies in LaCoO3

(Acquired in Titan G2 and ARM200F)

(Acquired in ARM200F)

(DFT calculations with VASP and CASTEP)

(Exercise for airshow in May)

2023

Protons vs. Metal Cations: Direct Visualization of pH-Dependent Charge-Carrier Insertion in V2O5

(Acquired in Talos F200X)

Strain-Induced Oxygen Release in LiCoO2 and Li2MnO3 without Electrochemical Cycling

(Acquired in Titan G2 and Talos F200X)

(Acquired in Titan G2 and Libra 200MC)

(Acquired in Talos F200X)

(Acquired in Titan G2)

(Acquired in Libra 200MC)

(Acquired in Titan G2, Libra 200MC, and Talos F200X)

(Acquired in Titan G2 and Libra 200MC)

(DFT calculations with VASP)

Dopant Segregation at Grain Boundaries in BaTiO3 for a New Class of Ceramic Capacitors with High Reliability

(Acquired in Titan G2)

(Acquired in Spectra Ultra 30-300)

(Acquired in JEOL JEM-ARM300F2)

(DFT Calculations with CASTEP)

First Direct Atomic-Scale Observation of Premelting inside a Crystalline Solid (BaCeO3 as a Model System)

Frederic A. Lindemann (Britain, 1886~1957)

(In 1910, he proposed a criterion of melting based on a vibrational instability (the root-mean-square displacement of atoms) in a crystal.) Lindemann Criterion

Max Born (Germany, 1882~1970)

(In 1939, he proposed another criterion of melting based on a rigidity catastrophe by the shear modulus vanishing in a crystal. He is also well-known for the statistical interpretation of the wave function - the 1954 Nobel Prize in Physics.) Born Criterion

(Acquired in Titan G2)

2022

Fe-Enhanced Oxygen Evolution Catalysis in LaNiO3 : Amorphous vs. Crystalline States

(Acquired in Titan G2)

(DFT Calculations with CASTEP)

2021

Local-Electrostatics-Induced Oxygen Octahedral Distortion in Perovskite Oxides

(Acquired in Titan G2)

(DFT Calculation with CASTEP)

(Acquired in Titan G2)

Multiple Phase Transformations during Hydrated Zn-Ion Insertion in V2O5

(Acquired in Titan G2)

(Acquired in Titan G2; Image simulations with Dr. Probe )

Contribution of d-Orbital States to Oxygen Evolution Electrocatalysis in Perovskite Oxides

(DFT Calculations with CASTEP)

(Acquired in Titan G2)

2020

Correlation between Crystal Structure and Stability in Iridate-Based OER Catalysts in Acid

(EDS Maps Aqiured in Talos F200X; STEM Images Taken in Titan G2)

Cu-Bi Antisite Intermixing and Its Influence on Polaron Hopping in CuBi2O4 for Photocathodes

(STEM Images Acquired in Titan G2)

(Atomic-Scale EDS Maps Acquired in Titan G2)

(DFT Calculations with CASTEP)

Strain Effect on the Generation of Ruddlesden-Popper Faults in Heteroepitaxial LaNiO3 Thin Films

(STEM Images Acquired in Titan G2)

(Acquired in Titan G2)

2019

Dissolution-Induced Surface Roughening in SrIrO3 and BaIrO3 for Enhanced OER Electrocatalysis in Acid

(Acquired in Titan G2)

(Captured in Titan G2; EELS with GIF Quantum965)

Perturbation of Oxygen Octahedra at an Atomic Level to Boost OER Activity in Perovskite Nickelates

(Captured in Titan G2)

(EELS with GIF Quantum965 in Thermo Fisher Titan G2)

(Captured in Titan Themis Z)

(DFT Calculations with CASTEP)

Thermally Unperturbed Cation Ordering in a Li Spinel Oxide: Impact of Locally Distinct Chemical Bonding

(Imaged in Libra 200MC)

(DFT Calculations with CASTEP)

2018

Grain Boundaries as Exceptionally Active Sites for Oxygen Electrocatalysis on Perovskite Oxides

(Captured in Titan G2)

Co Dissolution in Aqueous Electrolytes and Unusual Tetrahedral-Site Occupation Stabilized by Li/Co Vacancies in LiCoO2

(Captured in Titan G2)

(Captured in Titan G2 and JEOL JEM-ARM200F)

(Acquired with GIF Quantum-965 in Titan G2)

(Captured in Titan G2)

(DFT Calculations with CASTEP)

Control of Grain-Boundary Amorphous Phases for High Proton Conduction and Decomposition Tolerance in Perovskite BaCeO3 Polycrystals

(Captured in Titan G2)

2017

Space-Charge-Driven Dopant Segregation at Perovskite-Oxide Polycrystal Interfaces

(Captured in Titan G2)

(Obtained in Titan G2)

LaNiO3 Four-Leaf Clover by Oxygen Evolution Reaction

(Captured in Titan G2)

Two-Dimensional Homologous Faults and Oxygen electrocatalysis in LaNiO3

(Captured in Titan G2)

Nanoscale Gold Achieved by Reduced Anodization for Efficient CO2 Reduction

(Captured in Libra 200MC)

2016

High Proton Conduction via Clustering between Acceptors and Oxygen Vacancies in Perovskite BaZrO3 and BaCeO3

(DFT calcualtions with CASTEP)

(Captured in JEOL-JEM 2100F)

Subsurface Distribution of Antisite Defects in LiMnPO4 (Comparion with LiFePO4)

(Obtained in JEOL JEM-2100F)

First Direct Atomic-Resolution Evidence of Subsurface Space-Charge Segregation of Solutes in Oxides

Yakov (Jacob) I. Frenkel (Russia, 1894~1952)

(In 1946, Frenkel first postulated the presence of space-charge layers in the subsurface region in ionic crystals.)

Model material: Perovskite-type CaCu3Ti4O12 (or (Ca1/4Cu3/4)TiO3)

(Captured in Titan G2)

(Obtained in Titan G2)

(Captured in Titan G2; STEM image simulation with QSTEM)

(DFT calculations with CASTEP)

Vacancy-Induced Local Distortion of Oxygen Octahedra in (Ni,Mn,Co)O Showing High Pseudocapacitance

(DFT calculations with CASTEP)

Identification of Oxygen-Substituted Layers in Cu2ZnSnSe4 with High Power-Conversion Efficiency

(Obtained in Titan G2)

(Captured in JEOL JEM-2100F; STEM image simulations with QSTEM)

2015

Coherency Elastic Energy at Quadruple Junctions and Phase-Separation Behavior in LixFePO4

(Atomic-scale observation for the quadruple junction force equilibrium!)

(Geometric phase analysis)

(Captured in JEOL JEM-2100F)

Frenkel-Defect-Mediated Ordering Transformation in Li(Mn,Ni)2O4 Spinel

(Captured in Titan G2)

(Fourier-filtered image captured in Libra 200MC)

(DFT calculations with CASTEP)

Orientation-Dependent Subsurface Antisite Defects in LiFePO4

(Captured in JEOL JEM-2100F)

(DFT calculations with CASTEP)

Nucleation of Nanoscale Pits and Crystal Shrinkage in LiFePO4

2014

Layer-by-Layer Crystal Growth at High Temperature in LiFePO4

(Captured in JEOL JEM-1300S; image simulation with MacTempas)

2013

Layer-by-Layer Crystal Evaporation at High Temperature in LiFePO4

(Image simulations with JEMS)

2012

Distinct Configurations of Antisite Defects between LiMnPO4 and LiFePO4

(DFT calculations with CASTEP; images captured in JEOL JEM-ARM200F)

Cation Intermixing during Crystal Growth at High Temperature in LiFePO4

(Images captured in JEOL JEM-1300S)

2011

3D Visualization of Isolated Fe-Rich Phases without Percolation in LiFePO4 Matrix

(Captured in JEOL JEM-2200F)

Nanoprobe Measurement of High Electronic Conductance of Individual Nb-Doped LiFePO4 Nanocrystals

2010

Verification of Cations Doping in LiFePO4 Crystals

Confirmation of Multiple Phase Transformation during Crystalization in Nb-Doped LiFePO4

2009

First Direct Observation Proving "Ostwald's Rule of Stages"

Wilhelm Ostwald (Germany, 1853~1932)

Nobel Prize in Chemistry (1909)

Distribution of defects Is Not Random; 1-D Array of Antisite Defects in LiFePO4

Probing of Dopant Site Selectivity in CaCu3Ti4O12

2008

Direct Visualization of Antisite Defects in LiFePO4

(First Atomic-Scale HAADF-STEM Images in Li-Intercalation Compounds)

(Captured in JEOL JEM-2100F)

(STEM image simulations)

2007

Tunable I-V Characteristics by Donor Doping in CaCu3Ti4O12

2006

Success in Commercialization of Doped LiFePO4, "NanoPhosphates" (developed in 2002), as New Cathode Materials in Li-Ion Batteries

Nanoscale Lattice Bending in CaCu3Ti4O12

(Captured in JEOL JEM-4010)

2005

HREM Obervation & Correlation between I-V and High Permittivity in CaCu3Ti4O12

(Captured in JEOL JEM-3010)

2004

Strong Nonlinear I-V Behavior in CaCu3Ti4O12

2003

Verification of High Bulk Electronic Conductivity in Nb-Doped LiFePO4

Observation of Dislocations and Grain-Boundary Structures in Polycrystalline SrTiO3

(Captured in JEOL JEM-3010)

2002

Electronically Conductive Olivine LiFePO4 Nanocryatals and High-Power Properties for Li-Ion Batteries

2001

Control of Ionic Vacancies and Microstructure Evolution in SrTiO3

2000

Effect of Dislocations on Grain Growth in Polycrystalline SrTiO3

1998

Core-Shell Structure Formation in SrTiO3 by Oxygen Partial Pressure Change