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We demonstrate that a high-density 2DEG that is confined within a unit cell layer thickness in SrTiO₃ yields an enhanced ZT_2DEG value exceeding 2. In the optimized case, the |S| value for the 2D confined ne of 1.4×10²¹ cm^-3 is 850 μV⋅K^-1, which is ∼5 times larger than that of the 3D-bulk SrTiO₃ (170 μV⋅K^-1), while the 2DEG system retains the rather high σ_2DEG value of 1.4×10³ S⋅cm^-1, leading to a ZT_2DEG value of ∼2.4 at room temperature if κ value of bulk single crystal SrTiO₃ is used for the calculation.

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Thermally and chemically stable phenylsilsesquioxane (PhSiO3/2) particles were prepared by sol-gel process. Multilayers of oppositely charged poly(allylamine hydrochloride) (PAH) and poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) were alternately deposited on the negative-charged PhSiO3/2 particles via layer-by-layer assembly technique. Sheet-like electrolytes were obtained from the resultant core-shell particles by pressing. Proton conductivity of the PAMPS-deposited electrolyte sheet is discussed in relation to the amount of deposited PAMPS.

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Proton conductive membrane was fabricated using of layer structured zirconium phosphate (α-ZrP) with glycidoxypropyl-methyldiethoxysilane, which was intercalated with aminoethyl-aminopropyl-methyldimethoxysilane. The extended distance between layers of α-ZrP was estimated to be 2.64 nm by using X-Ray diffraction. The ionic conductivity of the membrane was estimated to be 4.2×10^-5 S/cm by AC impedance method at 80 °C, 80 % relative humidity.

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EDLC (Electric Double Layer Capacitor) sometimes called supercapacitors (or ultracapacitors), have attracted many attentions from all over the world. Power sources of such kind have varieties of applications because of their excellent characteristics such as high power density, long-term cycleability, maintenance-free and wide temperature-range operations. The lecture covers the basic introductions and state-of-the-art of capacitor materials and their science and technology in relation with nanotechnology. Specifically, the recent advances in nanocarbons(carbon nanotube, nanofiber), nano-sized inorganic(nanocrystal metal oxides and other nano-sized intercalation compounds/composites and organic materials of pai-condugated systems are reviewed.

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We investigated the effect of Al addition on the red emission upon band-gap excitation in perovskite-type oxide phosphors, SrTiO₃: Pr³⁺ from the viewpoint of defect chemistry. The results indicate that the increase in emission intensity by the addition of Al is attributed to the substitution of Al for Ti, which decreases the concentration of electronic carriers damaging the emission.

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The effect of a host structure on the emission properties of Eu²⁺ was investigated. By replacing the A site of A₃MgSi₂O₈ with Ba, Sr, or Ca, the crystal structure changes. When Ba is involved in the chemical formula, prepared sample became glaserite structure, while merwinite structure was obtained from a batch compsition Ba is not involved. From the results of fluorescence spectra measurements, it was confirmed that emission properties reflected each crystal structure induced by the kind of alkaline earth metal ion.

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When glass or isotropic solid are acted upon by stress, they show birefringence called photoelasticity. These stresses in optical devices such as glass fiber, sensor, waveguide and display panel and so on reduce optical properties, so photoelasticity becomes one of the important properties of optical materials. There are several methods for the analysis of photoelasticity. However, those methods bring the different photoelastic constant (PEC), because the retardation includes the strain and residual stress. In this work, the photoelasticity of Binary Phosphate glasses are studied by the retardation with road using frequency stabilized transverse Zeeman laser. This method is possible a precision measurement because of considering the stress as a vector factor.

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High purity forsterite (Mg₂SiO₄) ceramics is one of the millimeter-wave dielectric having high quality factor Qf and low dielectric constant t_f. However, it has a negative temperature coefficient of resonant frequency t_f between -60 to -70 ppm/C. Rutile (TiO₂) that owing high t_f value (+450 ppm/C) was added to the ceramics in order to adjust the tf to zero. Two kinds of powders were prepared: one with 25 wt% TiO₂ added, and another with 30 wt% TiO₂. We found that the nearly zero t_f can be achieved by controlling the sintering duration at 1200C. The relationship between microstructure and dielectric properties was investigated.

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We report the electrical conductivity of the mixed alkali silicate glasses in the system (60-x)SiO2-40Na2O-xCaO(x= 0~15 wt%) in the temperature range from 323K to 893K. This report was conducted for research about the relation between conductivity, composition and crystallization.

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Ion formed by gas was implanted in ZnO ceramics and single-crystal, and then was studied optical property and defects formation. Photoluminescence measurement revealed the stable peak position related with ion dose. In this paper, we would like show the relationship the position in PL spectrum and stable defects in detail.

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