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In order to reveal the oxygen diffusion through Ba0.95La0.05FeO3-(BLF), 18O2 vapor/solid exchange reaction were performed. Oxygen diffusion through BLF was observed by secondary ion mass spectrometry (SIMS). The relatively high oxygen diffusion and oxygen vacancy diffusion in BLF were estimated. From the diffusion data, it was found that the oxygen diffusion in BLF is attributed to the oxygen vacancy migration.

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We synthesized trivalent ionic conducting materials with NASICON-type crystal structures. (Al_xTi_1-x)_4/(4-x)Nb(PO₄)₃ (x = 0.0-0.5) solid solutions were obtained at 1373 K by employing solid state reactions. Further, single phases without impurities were obtained for contents x = 0.0-0.2. The Arrhenius plots of impedance measurements of sintered materials were linear, and impedance values were high. Subsequently, it can be expected that the electric conductivity increases with the Al content x, thereby enhancing charge carrier concentration. However, the electric conductivity does not increase simply with the Al content x. The influence of the content x in (Al_xTi_1-x)_4/(4-x)Nb(PO₄)₃ on electric conductivity was clarified.

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We prepared the rare earth iron garnet R₃Fe₅O₁₂ using a reverse coprecipitation method, and then nano-sized powder was prepared by bead milling. The maximum heat generation ability was obtained for Y₃Fe₅O₁₂. Magnetic moment of the sample did not influence the heat generation ability at all.

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Nano-sized Y₃Fe₅O₁₂ ferrite powder prepared by bead milling was calcined to clarify the effect of particle growth on the heat generation mechanism in AC magnetic field. The maximum heat generation ability of 0.46W•g^-1 (1.77kA•m^-1,370kHz) was obtained for the sample calcined at 700oC. Although the suparparamagnetic material was obtained for the sample calcined at low temperature, the ferrimagnetic property showed for that calcined at 700^oC (particle size 37nm).

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Photoluminescence (PL) of mesoporous carbon silica (MPCS) under UV light excitation is reported. The MPCS nanocomposite was synthesized by a triconstituent co-assembly method followed by carbonization at 900 ^oC in N₂ and oxidization at 500 ^oC in air. The PL color of MPCS nanocomposite was dependent on the HCl concentration which is used as a catalyst for stimulating hydrolysis and polycondensation. It is speculated that the PL color is effected from the location of C atom in SiO₂ and the framework structure of silica.

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Characteristics of the devitrification of silica glass containing 1000 wt. ppm of Cl by contact with a NaCl crystal grain were investigated. The characteristics were compared with various types of silica glasses containing Cl-free and various amounts of OH. We exhibited that Cl-contained silica glass has potential of suppression of devitrification. In XRD data, growth of tridymite in Cl contained silica glass was significantly smaller than Cl-free samples. The fact that the devitrification is suppressed in Cl-contained sample suggests that the growth of tridymite might be suppressed by chlorine in silica glass.

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In low-frequency region of Raman spectrum, glassy materials show an asymmetric broad band, so-called Boson peak. Although it has been suggested that position of the Boson peak is related to elastic property, there are few reports about the relation in actual glassy materials. In addition, Boson peak in binary Li₂O-SiO₂ system glass has not been examined so far. Therefore, in this study, we have prepared several glasses in the Li₂O-SiO₂ system, and investigated their Boson peak behavior. Relationship between the peak position and elastic property was also considered in binary M₂O-SiO₂ (M = Li, Na, K) system glasses.

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To date, there are many reports about electric/magnetic property in glass containing 3d-transitional metal (e.g., Fe³⁺ or Cu²⁺). On the other hand, crystallization behavior in their glasses has not been fully examined. Fe ion has interesting physical properties due to Fe-polyhedron, for example, multiferroic perovskite-type BiFeO₃. Therefore, in this study, we have prepared Bi- and Fe-containing phosphate/borate glasses.

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The purpose of this sturdy is to show a connection between Nd³⁺ chemical states and optical properties in oxyfluoride glass-ceramics. Nd³⁺-doped glass-ceramics were synthesized by a sol-gel method. A hydrofluoric acid treatment was applied to the glass-ceramics to remove SiO₂ component. This allowed us to obtain bare fluoride nanocrystals doped with Nd³⁺. The detailed optical measurement and structural analysis of Nd³⁺ were carried out using the obtained bare fluoride crystals.

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We have developed a method to prepare photoluminescent (PL) glass capsules incorporating quantum dots (QDs). Hydrophobic CdSe/CdxZn1-xS QDs capped with oleic acid (OA) were synthesized by an organic route. The QD-incorporated capsules were prepared by a two-step method. In Step 1, the QDs were silanized by using partially hydrolyzed tetraethyl orthosilicate (TEOS) via replacing OA on the QDs. In Step 2, the QDs assembled when introduced into reverse micelle with water. Then the QDs were encapsulated in glass capsules. The resulting water-dispersible capsules retained high PL efficiency because the QD surface was effectively protected in Step 1.

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A solution based hydrothermal synthesis at 200C followed by calcinations at 900C was used for the preparation of Y0.99-xPO4:Ybx/Er0.01 (x=0.10, 0.30, 0.50) nanoparticles. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and upconversion luminescence (UCL) spectra. All the samples were assigned as the tetragonal YPO4 phase. Under near-infrared laser excitation, the upconversion luminescence was observed, where the intensity increased with an increase in the Yb3+ doping content (x), indicating that Yb3+ acted as a sensitizer, which transfer the energy of near-infrared excitation to Er3+ illuminant.

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To date, crystallization of Cu-containing glasses in multi-component system has not been fully examined. On the other hand, in Sr-Cu-O system, there are several crystalline phase possessing intriguing thermal/electrical properties. In order to fabricate the functional glass-ceramics consisting of the Sr-Cu-O phases, we prepared glasses in SrO-CuO-B₂O₃ system by a conventional melt-quenching technique, and investigated their crystallization behavior.

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Up to now, most applications have used single crystalline scintillators. Previous study revealed that Y2O3 ceramic fabricated by the conventional sintering method showed better light yield than famous Bi4Ge3O12 (BGO) crystalline scintillator. This result motivates us and in this presentation we will report scintillation properties of Sc2O3, Y2O3 and Lu2O3 transparent ceramics made by spark plasma sintering (SPS) method which is a novel method to synthesize transparent ceramic. As a result, the gamma-ray excitation light yield of Sc2O3 ceramics was evaluated in about 1.4 times higher than that of BGO single crystal.

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Surface-Enhanced Raman Scattering (SERS) caused by Localized Surface Plasmon Resonance of gold nanoparticles is one of candidates of biosensing material application for organic molecular measurement with high sensitivity and selectivity. In this study, we've aimed to find out the gold nanoparticles with excellent SERS properties and figure out the SERS mechanism by preparing gold nanoparticles with a lot of branches. In this report, different types of gold nanoparticles were synthesized and their shapes and SERS spectra were investigated.

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Density is an important physical parameter for thermal flow simulation in a melting furnace. High-temperature density of simulated radioactive waste glass was measured by Archimedean immersion method between 1083K and 1273K and by Archimedean double-bob method from 1273K to 1573K. We found that the molar volume of molten waste glass is proportional to the log of temperature.

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This work reports for the first time synthesis of K₂La₂Ti₃O₁₀ and KLaNb₂O₇ doped with Er³⁺, Yb³⁺ and ther upconversion luminescent properties by 980nm excitation.

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In this work, Eu2+-doped Ba3Si6O12N2-type phosphors (Si/Ba=2-4) were prepared by solid state reaction, the variations of crystal structure and the photoluminescence properties on cationic compositions are discussed. These phosphors showed the maximum emission intensity at Si/Ba=2.5.They also showed the maximum tolerance rage of 60% for substitution by Sr at Si/Ba=3.

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It is well-known that NaGdF₄ nanocrystals are excellent host materials which have high upconversion photoluminescence (UCPL) efficiency. However, photoluminescence efficiency depends on their crystal structures of the host materials. Thus, it is necessary that each crystal phase of cubic and hexagonal NaGdF₄ is dominantly synthesized when photoluminescence properties are estimated. In this report, a hydrothermal synthesis method is used to synthesize NaGdF₄:Tm³⁺,Yb³⁺ nanocrystals. The purpose of this study is to investigate the synthesis conditions to obtain each phase(cubic, hexagonal) and the effects of crystal structures on blue upconversion photoluminescence excited by near infrared laser at 975 nm.

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Azobenzene (AB) doped inorganic-organic hybrid films were prepared via a sol-gel process. The absorbance of AB in the film was gradually decreased by drying at room temperature after the film preparation. The rate of absorbance decrease of phenylsilsesquioxane film was slower than those of the films with the other inorganic-organic matrices. The difference of the rate was attributed to the occurrence of an intermolecular pi-pi stacking interaction between phenyl functional groups and benzene rings of AB.

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A new rare-earth-free phosphor Zn₃(VO₄)₂ was developed in this work. The starting materials of V₂O₅ and ZnO were solved in hydrochloric acid or nitric acid and the obtained dried-precursors were heated at 500-1000 deg.C in a vertical-type tubular furnace under the atmospheric conditions. Nitric acid was more suitable for the preparation because the precursor prepared with hydrochloric acid provided a by-product phase of Zn2V2O7 together with Zn₃(VO₄)₂ with due to the vaporization of ZnCl₂ in the precursor, which does not show phosphorescence.

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In the present study, we have found a new compound in a Na-Sc-Si-O system. The synthesis of the new compound with a high phase purity was achieved when the sample was synthesized with a ratio of Na:Sc:Si = 3:1:3. The Eu2+-activated new compound showed a broad emission band with a maximum at 530 nm and a broad excitation bands up to 500 nm.

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Mn⁴⁺ is known to exhibit red luminescence, whose wavelength can be varied with host material and crystal structure, so as to be expected to be applied to display and illumination devices. In this study, we prepared Mn⁴⁺ doped Mg₂TiO₄ and MgTiO₃ so as to investigate their photoluminescence(PL) and photoluminescence excitation(PLE) properties.

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Photoluminescence properties of MgTiO3 thin film deposited by the pulsed laser deposition technique were investigated. Contrary to the spectrum for bulk MgTiO3, broad spectra around 605 nm was found to grow with the decrease of the target-substrate distance. The origin of the broad spectrum is discussed based on the defect chemistry of MgTiO3.

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0-40 mol% Eu₂O₃ doped Y₂WO₆ red phosphors were prepared by solid-state reaction. The samples fired at the range of 1673-1973 K for 2h in air were mostly a single phase except for non-doped ones. XRD revealed the crystal structure of Eu₂O₃-activated ones were similar with Nd₂WO₆ (PDF #72-1867) type structure. That is new high temperature phase was considerable amount of yttria doped Eu₂WO₆ (C2/c), not europia doped Y₂WO₆ (high temperature modification of P2₁2₁2₁). Best composition was about 25 mol% europia doped one fired at 1923 K. Emission spectra (lambda_ex.= 393 nm) showed strong peaks of 614 and 611 nm. Excitation spectra (lambda_em.= 614 nm) did strong peaks of 393, 464 and 535 nm.

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Submicron sized powder phosphors with localized emission center (i. e. ZnS:Mn) was prepared for powder type electroluminescence (EL) device. Mean diameter of Submicron sized ZnS:Mn powder prepared by planetary ball mill was below 1 um. It was larger than thickness of thin film phosphor. Therefore, to obtain a high electric field compared with the conventional powder type EL device, thin film dielectric layer (BaTa2O6) was inserted into the conventional powder type EL device.

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The use of the mechanoluminescence (ML) technique to directly observe dynamic instability is described. The positions, the slope angle of the band front and propagation velocity of the Portevin-Le Chatelier (PLC) bands was observed and captured in the ML images. The results show that real-time visualization of the PLC effect was achieved using this ML technique.

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