BaTiO₃ is well known for its excellent properties and applied to many fields such as multilayer ceramic capacitor. Well-dispersed slurry is required to prepare ceramic greensheets with good packing density and homogeneity. However, it is commonly difficult to disperse ceramic fine particles in aqueous solution. In this study, the effect of the addition of polyelectrolyte dispersants on dispersibility of aqueous BaTiO₃ slurries was investigated for the establishment of aqueous processing of BaTiO₃ ceramic sheets. The viscosity of slurries showed the minimum by adding 0.2mass% PAM under the controlled condition without leaching Ba(pH 9). Further the wettability of aqueus BaTiO-3 slurries to carrierfilm was improved by the addition of binder.

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Various studies have been reported on the chemical processing under a high magnetic fields. In the present study, porous ceramics bodies were fabricated through slip casting of hydroxyapatite based ceramics slurries under a high magnetic field and subsequently, their ceramic compactions were sintered at 1000∼1300°C without a high magnetic field. Additionally, hydroxyapatite based ceramics were in-situ sintered at 1000∼1300°C under a high magnetic field. The microstructures of both ceramics sintered bodies were evaluated by XRD technique and SEM observation. The effect of a high magnetic field on microstructure of ceramics was mainly investigated.

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A novel particle assembling technique using a local electric field has been investigated by electrophoretic deposition technique using a very small counter electrode (microelectrode), this is so-called μ-EPD process. Polystyrene microspheres (φ= 320 nm) were used as dispersed particles in ethanol suspension. A micrometer-size dots and its patterning can be successfully formed onto a desired position of an ITO-coated glass substrate by using this μ-EPD process.

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Alpha-alumina thick film was prepared by electrophoretic deposition using formed carbon powder as an electrode, to which various kinds of shapes can be added easily, and which can be burned out while sintering the deposited alumina powder. The surface texture of the obtained alumina film was affected by the surface texture of the carbon electrode, which can be controlled by the variety of the used carbon powder, i.e., graphite or carbon black. Moreover, the quality of the thick film largely depends on the kind of binder used for the preparation of the electrode.

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This study presented novel characterization method, polarized light microscopy, which can reveal particle orientation in green compact. Orientation degree was evaluated by measuring retardation. Relatively low orientation degree was detected by this method. It has not been able to detect by conventional XRD method. There is good relationship between orientation degree determined by XRD and polarized light microscopy.

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We researched fabrication of porous ceramics with controlled pores. Polystyrene (PS) colloidal particles have been used as templates to produce ordered macroporous silica structures. The silica-films were deposited tetraethyl orthosilane (TEOS). The silica coated particles and the film thickness were characterized using transmission electron microscopy and scanning electron microscopy. Fabrication of the coated particles was performed by centrifugation. Calciantion of the close-packed spheres yielded a continuous silica matrix consisting of a three-dimensional well-ordered network.

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The porous body is made by the method such as freeze dry, partial dissolution and foaming. In this study, the porous ceramics were fabricated by spinel formation from granular alumina and fine magnesia. The low linear shrinkage was indicated in the bodies fired at 1200∼1300°C. In the measurement of a mercury porosimeter, the pore exhibited the bimodal distribution and the pore volumes increased with the increasing firing time at 1200°C.

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Intelligent control of nano-particles dispersion or aggregation, and fabrication of minute parts by using molding-less method were studied. An optical functional group was introduced into the surface of the silica particles by using the cinnamyl alcohol of the ultraviolet photochemistry reactiveness as a surface modifier. This is a dispersibility improvement operation to the organic solvent at the same time. The crosslinking reaction between the modified silica particles by the light irradiation was examined by UV spectroscopy. As a result, it was confirmed that the ultraviolet irradiation was made a trigger, and the crosslinking reaction occurred between particles. This method applied to fabrication of porous materials.

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In this research, porous ceramics by gelcasting using a foamed slurry with waste resources were fabricated. The waste materials are glass from bottle waste, remnants of purified-clay and clashed tile. Porosity of porous ceramics was controlled by the change of forming agents and addition amount. Furthermore, the relation between porosity of porous ceramics and their properties such as flexural strength, sound absorption coefficient and thermal conductivity were investigated.

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Natural gels were used to the fabrication of porous ceramics consisting of waste resources by in situ solidification method. The effect of gel concentration on wet and green bodies was investigated. The strength of wet green bodies for compressive load increased with gel concentration. On the other hand, the flexural strength of dry green bodies depended on their porosity rather than on gel concentration.

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The occurrence of fracture in a drying process of slip-cast hollow green bodies for large potteries was investigated. In the slip casting process, the flow of the poured slurry was observed, and a weld line was formed in the green body by contact of the side surfaces of slurry. In the drying process, cracks were occurred at the weld line. It was found that the formation of the weld line in the slip casting is prevented by vibrating the plaster mold.

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A new direct casting method of aqueous high solids loading alumina slurries stabilized by ammonium polyacrylate has been developed. The dissolution of AlN into the alumina slurry gradually increased the ionic strength of its slurry, and finally the slurry coagulated to change its property from a viscous liquid to homogeneous, rigid, green body. The fired body with 99% T.D. was obtained through this new DC method.

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Particle orientation in the green body made by slip casting was evaluated by a novel method with polarized light microscopy. Degree of particle orientation was evaluated by retardation of green body against that of single crystal. Degree of particle orientation was10%-15%. The most oriented structure was observed at near section from gypsum mold. The shrinkage of sintering was discussed with density and degree of particle orientation.

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We report a novel method for characterizing the internal structure of granule compact of high reflective index. Resin with fluorescent dye was immersed into the compact. Cross section of compact with resin was observed by confocal laser scanning microscopy (CSLM). Network structure of deformed granules in the compact was observed. This method has a potential to observe an internal structure of granule compact with powders of high reflective index.

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In this study, the defect detected by the optical method was structurally analyzed. The experiments revealed that origin of a dark image region in an optically transparent image was resulted from the optical scattering at pores of which shape is sheet or shell with about or more 1μm width in ceramics.

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Relationship between packing structure and sintering shrinkage was studied in compact made by uniaxial and cold isostatic pressing. Particle packing densities in pressing direction was different from horizontal direction. This difference was disappeared with increasing CIPing.

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Pore structure was directly observed by dyeing of fluorescence in pores. The mixture of fluorescence dye and immersion liquid was filled into pores of alumina green body which was thinned previously. Images were obtained by a confocal laser scanning microscope. Several pictures were taken at a specific change of focusing position in the specimen. Three-dimensional pore structure was reconstructed from these pictures in a computer.

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A new evaluation technique has been developed for characterization of slurry compressibility by using constant pressure filtration. In order to estimate the packing fraction of formed cake, we modified Ruth's equation and experimental results were analyzed by using the modified equation based on not the filtrate but on the particle volume of formed cake. It was shown that cake packing fractions estimated by this modified equation agreed well with those obtained by measuring the volume and weight of formed cake.

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Slurry compressibility was evaluated by using constant pressure filtration. In order to estimate the packing fraction of formed cake, experimental results were analyzed by the modified Ruth's equation. It was shown that the packing fraction estimated by this equation agreed well with those obtained by measuring the volume and weight of formed cake. Therefore this method is useful for evaluation of the slurry compressibility.

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In this paper, it is explained that the hydrostatic pressure measurement method which is one of the techniques of the evaluation of slurry which we developed. The hydrostatic pressure measurement method is the technique to estimate the volume fraction of sediment by measuring the hydrostatic pressure at the bottom of settling pipe. Using estimated the volume fraction of sediment, the quality of slurry can be quickly and handily evaluated.

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T1:In this paper, it is explained that the measurement example which used the hydrostatic pressure measurement method. The slurry was used alumina powder and was prepared with HCl. At the results, the difference of the settling pattern was indicated by the pH. By comparison of volume fraction of sediment at initial settling, the quality of slurry could predict.

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Rubber lsostatic Pressing (RIP) is a new powder compaction method for near-net shaping. Though it was developed for producing green compacts of permanent magnet powders, recently, it becomes to be applied to not only magnets but also many other materials of metal or ceramics. In this paper, principle of RIP is explained, and then, forming performance is estimated by using metal powders. Moreover, a ceramic ornament is introduced as a new application of RIP.

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It is important to evaluate the properties of slurry in many industries such as ceramics, coating and so on. It is because the quality of ceramics products are strongly expected to be predicted by the test of slurry. In this study we propose the evaluation theory used ultrasonic attenuation in the various condition of slurry.

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It is important to evaluate properties of slurry in many industries such as ceramics, coating and so on. It is because the quality of ceramics products are strongly expected to be predicted by the test of slurry. In this study we discuss the relationship of attenuation distance and intensity in the various condition of slurry.

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Slurry compressibility was evaluated by using three different methods; constant pressure filtration, hydrostatic pressure measurement and ultrasonic attenuation method. In order to discuss the effect of solid concentration on slurry compressibility, the initial solid concentration was changed 1.0-35vol%. It was found that these methods could be useful to determine optimum conditions for slurry preparation more appropriately and more quickly than the traditional sedimentation method.

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Slurry compressibility was evaluated by using three different methods; constant pressure filtration, hydrostatic pressure measurement and ultrasonic attenuation method. In order to discuss the effect of dispersant amount on slurry compressibility, the dispersant amount was changed 0.16-0.60g/100gAl2O3. It was found that these methods could be useful to determine optimum conditions for slurry preparation more appropriately and more quickly than the traditional sedimentation method.

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The soda-lime-silicate glass is widely used as bottle, board, electric bulb, and window glass. Purpose of this study is to clarify the relationship between density and viscosity of soda-lime-silicate glass melts. The viscous curve was extrapolated with the volume expansion coefficient from the density measurement. In conclusion it is shown that the glass with low volume expansion coefficient above the Tg is Strong liquid.

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Mechanical properties of glasses in the system Sm₂O₃-Bi₂O₃-B₂O₃ and transparent TeO₂-based glasses and glass-ceramics (15K₂O.15Nb₂O₅.68TeO₂.2MoO₃) consisting of nanocrystalline particles and showing optical second harmonic generation were evaluated by means of nanoindentation test following the ISO14577. The Sm₂O₃-Bi₂O₃-B₂O₃ glass has a Martens hardness that fluctuates between 4.57 GPa and 6.61GPa in function of applied load and has an Indentation hardness that fluctuates between 6.95 GPa and 13.15 GPa. The transparent TeO₂-based glass-ceramic heat-treated at 410°C show an Elastic modulus (E) that fluctuates between 56.1 GPa and 92.1GPa. The values of Poisson ratio (v) and Elastic modulus were also estimated by means of cube resonance method, showing v = 0.22 and E = 69.68 GPa in the case of transparent TeO₂-based glass-ceramic heat-treated at 410°C.

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Crack initiation load(CIL) of various oxide glasses were studied under indentation and scratch test conditions. CIL depended on the composition of glasses. The similar relationships between CIL and composition were observed both in indentation and scratch tests.

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CuO_y-ZnO-P₂O₅ and CuO_y-BaO-P₂O₅ glass systems (0.5+ ion in the glasses. It is considered that this is related to the decrease in cross link density with the addition of 2-fold coordinated coppers in glass. In addition, it is found that a lower basicity of CuO_y-ZnO-P₂O₅ glass than that of CuO_y-BaO-P₂O₅ is responsible for the relative stability of Cu⁺ ion in the glass.

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Crushing a glass causes the structural change nearby the fractured surface, but its detail has not been clearified yet. In this study, crush-induced increase in internal energy and its thermal relaxation were examined by measuring the heat of solution to HF(aq). The crush-induced increase of internal energy of lead silicate glass was much smaller than that of silica glass. This should be due to the fact that the small free volume in lead silicate glass reduces the ability of structural change caused by mechanical stress. The behavior of the soda-lime glass was intermediate of above-mentioned two glasses.

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Photoluminescence (PL) spectra and absolute luminescence quantum yields of sol-gel-derived Al₂O₃-SiO₂ glasses were investigated. The Al₂O₃-SiO₂ glasses exhibited a strong white luminescence originating from carbonyl radicals. The internal and external luminescence quantum yields were ∼60% and ∼16% for the ethanot-soaked Al₂O₃-SiO₂ glass heated at 500°C.

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Intense mechanoluminescence(ML) has been observed in Mn-doped zinc silicate phosphor with the naked eyes in the dark atmosphere. The ML spectrum agrees well with photoluminescence. The ML intensity increases with increasing the mechanical stress. We assume that the ML of Mn-doped zinc silicate phosphor arises from piezoelectric effect and electroluminescence.

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The preparation of the high silica glass with high ultraviolet transmission is reported. The alkali borosilicate glass with a little of oxidizing agent was phase separated and the impurity of the Fe ion in the SiO₂-rich phase was decreased.The high silica glass thus obtained after acid-treated was sintered and the glass sintered exhibited an excellent transmittance up to the 185nm. The preparing procedure and effect of the oxidizing agent were investigated.

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The effects of the heat treatment on the optical quality of phenyltriethoxysilane (PTES)-derived organic-inorganic hybrid spherical particles were investigated. PTES-derived spherical particles were prepared by the vibrating orifice method. When the particles were heat-treated on the slide glass plate, there were some survived ones which remain their spherical shape at 400°C depending on the condition of the sol preparation. The survived particles also showed high photo-stability against 514.5nm Ar⁺-ion laser with a power of 120mW/paticle. In this study, the origins of their high thermal and optical stability are discussed.

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Transparent optical nonlinear crystallized glasses with Sr_xBa_2-xTiGe₂O₈ crystals have been successfully fabricated from glasses with stoichiometric and Sr-substitution compositions of Ba₂TiGe₂O₈ crystal, i.e., xSrO·(40-x)BaO·20TiO₂·40GeO₂, by means of careful heat-treatment in the temperature region of 670-700°C for 3h. Their second-order optical nonlinearities have been quantitatively evaluated using Maker fringe technique. As a result, of the increase in c/a axis ratio bring about the increase in second-order optical non-linearity of crystallized glasses have been cleared.

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Crystallization behaviors of RE₂O₃-Bi₂O₃-B₂O₃ glasses (RE=La, Sm, Gd and Dy) were investigated to clarify the relation between the precipitated crystalline phases and second harmonic (SH) intensity. Crystalline phase was carried out by XRD. SH intensity was measured by powder method. Strong SH intensities were observed from precipitated crystalline RE_xBi_(1-x)BO₃ phases. The SH intensity increased with the substitution of RE₂O₃ for Bi₂O₃. The RE_xBi_(1-x)B0₃ phases are phase-matching crystals.

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A monolayer of self-assembling gold(Au) nanoparticles was fabricated on a silane-coupling glass substrate. It was demonstrated in this study that optical second harmonic generation of the monolayer stemmed from a coupling mode of surface plasmon resonances of two or more aggregated Au@SiO₂ nanoparticles, which could be observed at ∼660 nm in optical transmission.

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A nonlinear optical (NLO) microscope has been developed in order to observe the crystalline phase morphologies of surface-crystallized glasses with optical nonlinearity. The observation and quantitative evaluation of the second harmonic generation images are quite effective for the assignment of NLO crystalline phases and their orientation.

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Second-harmonic generation has been observed in optically poled tellurite glasses doped with V₂O₅. The optical poling has been performed by using fundamental wave at 1064 nm and second-harmonic wave at 532 nm from picosecond pulsed Nd:YAG laser. The results of SHG measurements indicate that the poling with picosecond pulsed laser could induce second-order nonlinear properties larger than that with nanosecond pulsed laser. Large electric field of picosecond pulse seemed to influence the writing efficiency of second-order nonlinearity.

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Au and Ag-nanoparticle dispersed CaF₂ films (Au:CaF₂ and Ag:CaF₂) were prepared by laser ablation (pulsed laser deposition) using Au and Ag-powder mixed CaF₂ sintered targets. After heat treatment in Ar, Au particles were spherical in shape with the mean diameter of 5 nm and uniformly dispersed into CaF₂. The optical absorption spectra due to surface plasmon resonance of Au and Ag nanoparticle were observed at a wavelength around 538 and 408 nm respectively. With increasing the mean diameter of nanoparticle, absorption peak position is blue shifted and coefficient is increased.

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Using a sol-gel method, AuCu colloids synthesized in solution were introduced into a glass matrix, which were investigated using XRD, TEM and EDS, it was found that a reduction treatment in N₂ atmosphere allowed AuCu nanoparticles to be formed in the glass. Consequently, the surface plasmon resonance (SPR) in optical absorption could be changed from 525nm of Au nanoparticles to longer wavelength as the AuCu nanoparticles were precipitated.

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Thin silica films dispersed with silver nano-sized particles were prepared by evaporation-condensation method on sol-gel derived films to enhance the sensing ability. Surface plasmon resonance (SPR) absorption peak wavelength was measured by immersing films in liquids which had different refractive indecies n. It was shifted toward a longer wavelength with increasing n of liquids. Sensitivity for refractive index dλ/dn was large compared to that prepared by sol-gel method, and its value was 76.5.

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CuBr particle-dispersed glasses were prepared by ion-exchange using Copper staing method. The depth profiles of Cu ions and CuBr nanoparticles from the glass surface were measured by EDS and absorption spectroscopy. The Cu distribution monotonically decreased from the glass surface while the CuBr nanoparticle distribution showed the maximal peak near the surface.

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C₆₀-doped low-melting glasses have been synthesized from a mixture of R_nSi(OEt)_4-n and R_nSiCl_4-n by the modified sol-gel method. Nonlinear optical properties of the obtained glass were investigated by the Z-scan method.

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Two-photon absorbers were used as power stabilizers in order to stabilize the output of a laser whose pulses have a large degree of fluctuation from shot to shot. Optical stabilizing was measured by fixing a sample near the focus of Z-scan optical system. The Q-switched Nd:YAG laser generating 10 Hz, ∼5 ns pulses at 532 nm was used as the light source. For the purpose, we recorded histograms of the laser irradiance fluctuation using PbO-containing glasses with large two-photon absorption coefficient(β) as a stabilizer. In the present case, the fluctuation was reduced by about 10%.

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We have investigated the stability of photo-induced color centers in soda-lime silicate glasses of a) basic composition (74SiO₂·6Na₂O·10CaO in mol%), b) basic composition with 0.07wt% Fe₂O₃ and c) basic composition with 0.07wt% Fe₂O₃ melted at oxiding condition. The fading ratio of the absorption intensity due to photo-induced hole centers at 50°C during the period of 2-9 months after X-ray irradiation decreased in the order of a), c), b), while that during the period of one month after X-ray irradiation decreased in the order of b), c), a).

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The fading behaviour of photo-induced coloration due to non-bridging oxygen hole centers was analyzed under the assumption that the recombination of a hole and a trapped electron is the first order reaction through a thermally activated process of the electron. For several types of distribution function of activation energy, the parameters of the functions were determined so that the calculated decay curves were well fitted to the experimentally obtained curves.

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Silica glass was densified by applying high pressure and high temperature, and was irradiated by focused CO₂ laser light. A sharp bump was formed on a broad bump in the irradiated area. We can produce micro lens whose optical properties are not different from those of substrate. The height of sharp bump increased with an increase in laser power to the critical laser power. In contrast, the height of the broad bump was little changed. Both the height of sharp and broad bumps decreased by the irradiation above the critical laser power.

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When the focused laser light was irradiated on the glass surface, we observed the formation of the projection called bump on the glass surface. Thus we have demonstrated the formation of the micro-bump on the Co-doped SiO2-Na20-CaO and SiO2-B2O3-Na2O-CaO glass surface by using YAG laser.

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