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Aluminum nitride (AlN) has emerged as an important material due to its outstanding properties. Reactive plasma nitriding of Al₂O₃ powder is suitable for in-situ formation of AlN/Al₂O₃ coatings. This study investigated the effect of using fine particles and AlN addition on the fabrication process. Thick and uniform AlN/Al₂O₃ coating with high nitride content and very small amount of alpha-Al₂O₃ was fabricated. The fine particle size assisted the nitriding conversion (due to increasing the surface area) and AlN additives increased the nitride content in the coating. Furthermore, the nitriding species (N₂, H₂) hardly affect the phase composition, coating microstructure and hardness.

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Sintering of Al2TiO5 ceramic ladles by microwave heating was investigated on the base of an isothermal barrier structure, which consisted of an inner blanket (composed of -alumina and -alumina) and an outer one (fibrous alumina-silica board). The thermal and mechanical properties of the ladles were examined.

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We prepared the apatite-type lanthanum silicate polycrystals by reactive diffusion. The formation of apatite at 1773 - 1873 K was controlled by the interdiffusion of La2O3 and SiO2 components within the growing apatite layer. The highly c-axis-oriented polycrystalline material with 0.09 ≤ x ≤ 0.13 showed the oxide-ion conductivity ranging from 2.4 × 10-3 Scm-1 at 573 K to 2.39 × 10-2 Scm-1 at 973 K, with the empirical activation energy being 33.8 kJ/mol (= 0.35 eV). The reactive diffusion technique could be widely applicable to the syntheses of highly grain-oriented ceramics as a new facile texturing method.

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SiC nano-sized powder is promising as a starting material for structural and functional components. The properties of the final products are dependent on sintering behaviors of the SiC nanoparticles, on which impurities on the powder-surface significantly affect. In this study, micro-chemical and -structural analyses of the surface impurities were implemented. The combinations of X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy and Raman spectroscopy were effective to identify the impurities on the topmost surface of the nano-sized powders.

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The aerosol deposition (AD) method is unique coating technology based on collision of solid state fine ceramic powder with a substrate. This coating method has many advantages such as high deposition ratio, low process temperature, high adhesion force with a substrate. During collision of fine particles and interaction with substrate, these ceramic particles formed thick, dense and hard ceramic layers at room temperature. No additional heating for solidification of ceramic powder was required. We named this phenomenon Room Temperature Impact Consolidation (R.T.I.C). In this presentation, we explain the bonding mechanism of ceramic fine particles with RTIC on AD process.

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Microwave dielectrics have been used for mobile communication because of friendly with microwave, and miniaturization of the equipment. Though the utilization reduced because of limits of the miniaturization in mobile phone, they are still useful for microwave communications. New applications of the microwave dielectrics are expected based on the properties: low dielectric losses, dielectric constants, and temperature coefficient of resonant frequency. In this paper, the dielectric losses are discussed.

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By control of air-flow separation on wing surface of windmill using plasma technology, Out put power is improved. To a dielectric used for an electrode to produce plasma, the high electric discharge durability and the environmental resistance are required. Silica doped silicone rubber showed the superior electric discharge durability and the environmental resistance. The damage by the electric discharge examination was less than 10 micrometers.

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Recently, vibration energy harvesting is receiving a considerable amount of interest. For the piezoelectric vibration energy harvester, the piezoelectrics with low dielectric permittivity and large piezoelectric coefficient are suitable to obtain high conversion efficiency. In this study, BiFeO₃ is focused as one of the promising materials for piezoelectric energy harvester, because BiFeO3 has relatively low dielectric permittivity (~50). The piezoelectric properties of the BiFeO₃ films with different crystal system and orientation were characterized. It was found that the (100) BiFeO₃ films with rhombohedral structure have the largest effective transverse piezoelectric coefficient (e_31,f) of -3.5C/m².

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The commercial piezoelectric bimorph consisting of FRP plate (105mm x 10mmx 1.6mm) and two PZT ceramics (10mm x 34mm) were used in this experiment. The bimorph was oscillated by vibration generator. The voltages across the load resistor were measured by oscilloscope. The output voltage and power with the oscillation of 74Hz frequency and 1.32mm p-p displacement are evaluated. Generally, the output voltage increased with load resistance, maximum power was obtained in the measurement using load resistance of 30kohm.

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High energy harvesting utilizing piezoelectric buzzer was investigated. While external force was applied to the buzzer, PZT unimorph in the buzzer generated resonance vibration. As a result, alternating electric charges were observed. After rectifying, the charges were applied to LED, and new devices such as night-view footwear were developed. It was confirmed that the energy harvesting by this method is one of an effective tool to obtain clean energy.

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Spontaneous polarization (Ps) of Pb(Zr, Ti)O3 were investigate using polar-axis oriented tetragonal and rhombohedral epitaxial films. Observed Ps was in good agreement with the thermodynamic prediction reported by Haun et al.

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We have deposited PZT thin films and bottom oxide electrodes on Si substrate by chemical solution deposition (CSD) method. Both saturation polarization and residual polarization of the PZT films have increased when they were prepared on LaNiO3 (LNO) and (La,Sr)MnO3 (LSMO) electrodes. It was obviously shown that in-plane compressive stresses applied to the PZT film resulted in enhanced ferroelectric properties of the PZT film. In the present study, microstructure and crystal structure modification of the thin film was analyzed by TEM.

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A well-crystallized PMN thin film on a Si wafer was prepared using low-temperature processing with a LNO seeding layer. The PMN thin film was crystallized at 550 C on a LNO/Si stacking structure. Additionally, we attempted to apply the compressive residual stress to PMN layers for a Curie temperature shift. Results show that the ferroelectric property remained at room temperature. The remanent polarization increased concomitantly with increasing annealing temperature.

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For mixed anion oxides, the least commonly encountered substitution is where the hydride anion (H^-) replaces oxygen to form an oxyhydride. Only a handful of oxyhydrides have been reported, so far. Here, we present an oxyhydride of BaTiO₃, as an O^2-/H^- solid solution with compositions up to up to BaTiO_2.4H_0.6. BaTiO_3-xH_x is electronically conducting, and stable in air and water at ambient conditions. Furthermore, the hydride species is exchangeable with hydrogen gas at 400°C. Such exchange implies diffusion of hydride, and interesting diffusion mechanisms specific to hydrogen may be at play.

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Oxyhydrides of the solid solution (Ca, Sr, Ba)TiO_3-xH_x have been prepared by reducing the corresponding oxides with calcium hydride. Under the reaction conditions examined, a hydride content of x = 0.1 to 0.3 was obtained for all compositions. We examined changes in cell volume, octahedral tilt angle, and the site occupancy of different anion sites after conversion to oxyhydrides. We also examined the hydrogen release temperature, which showed an interesting trend against the A-site composition.

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Epitaxial thin film of titanium oxyhydride ATiO_3-xH_x (A = Ba, Sr, Ca) were prepared by CaH₂ reduction of epitaxial ATiO₃ thin films deposited on a LSAT substrate. Secondary ion mass spectroscopy detected a substantial amount and uniform distribution of hydride within the film. As opposed to bulk BaTiO_3-xH_x, the electric resistivity of all the ATiO_3-xH_x films exhibited metallic temperature dependence, revealing that the titanium perovskite oxyhydrides are intrinsically metallic. Treatment with D₂ gas results in hydride-deuteride exchange of the films. Combined with the materials' inherent high electronic conductivity, new mixed electron-hydride ion conductors may also be possible.

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La_1-xSr_xMnO_3-d (LSMO) thin films were developed as a smart radiation devices (SRD) for the future thermal system in satellites. LSMO films were deposited on several kinds of substrates and annealed in the ambient atmosphere. The metal-insulator transition temperatures were determined from magnetization curves and the emissivity of each LSMO film was measured by FT-IR as a function of ambient temperature. LSMO film with metal-insulator transition at room temperature showed the emissive change that was comparable with that of bulk LSMO during the transition. It was found that the amount of oxygen vacancies in LSMO films has more influence on the metal-insulator transition temperature than residual stress.

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Oxynitrides have attracted a great deal of interest, particularly for photocatalysis, but it is hard to optimize the O/N ratio precisely. Using the reducing agent CaH₂ on oxynitrides is expected to remove O^2- selectively, or perhaps even lead to the synthesis of mixed anion compounds with three types of anions (O^2-/H^-/N^3-). With the oxynitride perovskites La_xSr_1-xTiO_3-xN_x (0 ≤ x ≤ 1), we succeeded in preparing oxynitride-hydrides for 0 ≤ x ≤ 0.2, while the reduction reaction was not observed in 0.2 ≤ x ≤ 1. This result suggests that N^3- inhibits oxide reduction or H^- diffusion throughout the bulk.

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Blundred et al. mentioned that under reducing conditions, the pyrochlores RE₂Ti₂O₇ with larger lanthanide cations (RE = Sm, Eu) change their structure into perovskite RETiO₃. In this study, we reduced the pyrochlore Eu₂Ti₂O₇ by annealing in an evacuated tube with a metal hydride. According to the X-ray powder diffraction, the reduced sample has a perovskite structure, and TG measurements in air suggest the perovskite is deficient in oxygen. Furthermore, a considerable emission of hydrogen during heating under inert atmosphere was observed by TG-MS. This implies that at least in our case, this perovskite reported by Blundred et al. is in fact an oxyhydride, EuTiO_3-xH_x.

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Seger formula is important for the students who study a porcelain glaze in a scientific viewpoint. However, seger formula calculation process is complicated and, it takes a long time that students understand it. Then, we created a calculation software for preparation of glaze by Microsoft Excel VBA. In this session, the effective lesson which used this calculation software is introduced.

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New education program for growth of voluntary leaders is preformed in our university. We are responsible for the "Crystal materials Science" carrier house in the program. In this presentation, we introduce the system and activity of this carrier house.

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Epitaxial (111) Zn ferrite (ZFO) film with 50 nm thick was deposited on (001)YSZ substrate using KrF eximer laser PLD (pulsed laser deposition) apparatus. 0.1-10mol% Ti doped Zn ferrite (ZFTO) homo-epitaxial thin films with (111) orientation were deposited on ZFO buffered YSZ substrate as ZFTO/ZFO/YSZ structure. ZFO film on YSZ (ZFO/YSZ) showed higher electrical resistivity then the ZFTO/YSZ film. The resistance of the homo-epitaxial ZFTO/ZFO/YSZ film decreased with increasing the NO2 gas concentration. There was a good relationship between sensitivity and NO2 concentration in case of ZFTO(8nm)/ZFO(20nm)/YSZ film.

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