Aberration correted electron microscopy (ACEM) has improved resolution to sub-angstrom regime, which allows us to study materials with light elements, with dopants and defects, and with electronic, magnetic and optical functions. Developments of ACEMs and applications that undertaken in the world are briefly reviewed, being focused particularly on 50 pm resolution STEM and TEM instrumentation.

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  Recent development of spherical aberration correction in high-resolution transmission electron microscopy (C_s-corrected HRTEM) is reviewed by focusing on its application to nano-materials. Basis of the HRTEM imaging and new scientific advantage of C_s-corrected TEM are summarized, and recent applications of the method to high resolution imaging and selected area electron diffraction of nano-materials and interfaces are described as well as explaining its characteristic and the future prospects.

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  Interfaces in ceramics play an important role on the various properties. It has been known that the addition of small amount of dopants strongly improve the mechanical and functional properties in polycrystalline ceramics. Z-contrast images obtained by scanning transmission electron microscopy (STEM) is powerful technique to experimentally determine the location of the dopants segregated at grain boundaries and interfaces. As the image intensity in the Z-contrast is approximately proportional to the square of the atomic number, STEM technique is especially well suited for understanding the role of heavy impurities in grain boundaries and interfaces composed of much lighter ions. In this review paper, our recent results obtained for ceramic grain boundaries and interfaces by Cs-corrected STEM are introduced. Several examples are demonstrated for the gain boundaries of varistor and structural ceramics, dislocation in alumina, oxide superlattice, lithium battery and so on. These results indicate that the atomistic mechanism of the properties can be unraveled by the combination of STEM characterization and the first principles calculations. This approach will be a breakthrough for new materials science and engineering in the next generation.

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  Three techniques of wave field reconstruction using focus modulation transmission electron microscopy are reviewed based on a fundamental concept of three-dimensional optical transfer properties. These techniques use a set of through-focus images for the processing and enable not only correction of spherical aberration but also separate imaging of the phase and amplitude components of the sample. Defocus-image modulation processing enables real-time correction of spherical aberration by combining techniques such as high-speed control of focus and high-speed image processing. Three-dimensional Fourier filtering enables correction of all Seidel aberrations including spherical aberration and higher-order aberrations with high signal-to-noise ratios. Dynamic hollow-cone illumination combined with image processing using Fourier filtering has the possibility of reducing the degradation of spatial resolution caused by chromatic aberration. Experimental data obtained by these methods are presented describing the inherent characteristics of the respective methods.

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  A domestic spherical aberration corrected 300 kV transmission electron microscope named R005, which stands for 0.05 nm resolution, was developed. It has double aberration correctors in probe-forming and image-forming systems for high-resolution scanning transmission electron microscope (STEM) and conventional transmission electron microscope (TEM) observation. Asymmetric corrector optic system was developed to compress the parasitic aberration and the increase of chromatic aberration. Automatic aberration correction systems for STEM and TEM have been implemented. Neighboring atomic columns of Ga (63 pm spacing) in a GaN [211] crystalline specimen was resolved in a high angle annular dark field (HAADF) STEM image for the first time.

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  Gold has long been neglected as a catalyst because of its chemical inertness. However, when gold is deposited as nanoparticles on carbon and polymer materials as well as on base metal oxides and hydroxides, it exhibits unique catalytic properties for many reactions such as CO oxidation at a temperature as low as 200 K, gas phase direct epoxidation of propylene, and aerobic oxidation of glucose to gluconic acid. The structure-catalytic activity correlations are discussed with emphasis on the contact structure, support selection, and the size control of gold particles. Gold clusters with diameters smaller than 2 nm are expected to exhibit novel properties in catalysis, optics, and electronics depending on the size (number of atoms), shape, and the electronic and chemical interaction with the support materials. The above achievements and attempts can be regarded as a modern alchemy that creates valuables by means of the noblest element with little practical use.

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  Au colloid have characteristics of surface plasmon resonance with absorption at 500 nm~600 nm wavelength. Surface on the citric acid Au colloid can be conjugated with protein eg. antibody. Various particle size of Au colloid makes it high sensitive immunochromato as diagnostics. High sensitive immunochromato will be useful for application of cancer marker eg. prostate specific antigen and influenza early diagnosis.

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  In order to reveal the electron transport properties of 2D superlattices of small nanoparticles, establishing a general fabrication technique of well-ordered small metal nanoparticle superlattices with narrow interparticle spacings (small tunneling resistance) is indispensable. We have succeeded in the fabrication of self-assembled 2D superlattices of small Au nanoparticles stabilized by bidentate thiolate ligands terminated with π-conjugated aromatic groups with tuning the interparticle spacings. The stable and monodisperse Au nanoparticles smaller than 2 nm are easily prepared by the reduction of HAuCl₄•4H₂O in DMF/H₂O in the presence of a series of bidentate ligands, 2,6-bis(1′-(n-thioalkyl)benzimidazol-2-yl)pyridine. These small nanoparticles form hexagonal close packed (hcp) 2D superlattices with tunable interparticle spacings (1.2 nm to 2.5 nm), produced by changing the length of the ligand at not only the hydrophobic amorphous carbon but also the air-water interface. Long-range ordered hcp 2D superlattices were fabricated through the cleavage and construction of interligand π-π interactions formed via an annealing process at the air-water interface.

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  Metal nanoparticles possess unique properties that they do not exhibit in their bulk states. One of these properties is the color due to surface plasmon resonance. Gold nanoparticles appear red. This color has been utilized in glass for a long long time. In recent years, highly concentrated pastes of gold and silver nanoparticles have been successfully produced by using a special type of protective polymer and a mild reductant. The paste of gold nanoparticles can be used for paint and other materials as red colorants.
  In this article,application examples of gold nanoparticles as colorant are introduced.
  Recently, methods for producing bimetal nanoparticles such as gold/silver and gold/copper have been developed. These nanoparticles allow colors from yellow to green to be created. These methods and colors they produce are also described in this article.

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  Ferromagnetic spin polarizations on the samples of Au nanoparticles surrounded by protectives were observed by MCD method on X-ray (XMCD) of Au L₃-edgge to investigate the origin of the spin polarization. The consistency between both magnetization data by SQUID and XMCD are quite well and the result means that the observed magnetization is originated from the Au-nanoparticle itself. The protectives make some slight effect on the magnetization, but the protective of DT (Dodecane thiol) makes quite big reduction of the magnetization. The protective dependence directly means that the origin of the spin polarization arises from the surface of the nanoparticles. Diameter dependence of the surface magnetization on Au-nanoparticles is linearly decreasing with increasing diameter and the data sharply close to the value of bulk state Au-metal at the diameter of 4 nm. The results also make us infer close relation between surface and magnetization and the possibility of wide applications of nanosized materials.

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  We have developed an electron electron ion coincidence (EEICO) apparatus for high-resolution Auger photoelectron coincidence spectroscopy (APECS) and electron ion coincidence (EICO) spectroscopy. It consists of a coaxially symmetric mirror electron energy analyzer (ASMA), a miniature double-pass cylindrical mirror electron energy analyzer (DP-CMA), a miniature time-of-flight ion mass spectrometer (TOF-MS), a magnetic shield, an xyz stage, a tilt-adjustment mechanism, and a conflat flange with an outer diameter of 203 mm. A sample surface was irradiated by synchrotron radiation, and emitted electrons were energy-analyzed and detected by the ASMA and the DP-CMA, while desorbed ions were mass-analyzed and detected by the TOF-MS. The performance of the new EEICO analyzer was evaluated by measuring Si 2p photoelectron spectra of clean Si(001)-2×1 and Si(111)-7×7, and by measuring Si-L₂₃VV-Si-2p Auger photoelectron coincidence spectra (Si-L₂₃VV-Si-2p APECS) of clean Si(001)-2×1.

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