The effects of carbon content on the tribological behavior of titanium carbonitride(TiC_xN_1−x) films have been studied herein. A set of titanium carbonitride(TiC_xN_1−x) films was prepared by arc ion plating with a pure Ti target and a gas mixture of C₂H₂/N₂ on a steel substrate. High-definition field-emission scanning electron microscopy (FESEM) was used to investigate the microstructure of the films. The chemical composition of the films was analyzed using both electron dispersion spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) analysis. The surface roughness and microhardness of the films were measured using α-step profilometer and nanoindenter respectively. The tribology of titanium carbonitride(TiC_xN_1−x) films was investigated using a ball-on-disc testing method and the wear tracks were observed by low-magnification SEM. The tribological behavior of the films was significantly changed with variation of the C₂H₂/N₂ gas ratio. A very low friction coefficient (0.07) of titanium carbonitride(TiC_xN_1−x) film was observed when the C₂H₂:N₂ gas ratio was about 3:2.

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The effect of nano-Yb₂O₃ additive on crystallization and sintering behavior as well as its properties were investigated using fused quartz powder as raw material and nano-Yb₂O₃ as additive with dosages of 1% to 3% respectively after sintering at 1300 to 1400°C for 1 h. The results showed that cristobalite as the main crystal phase deposited while the sintering temperature was above 1300°C, and with increasing of sintering temperature, the amount of deposited cristobalite increased. Keiviite (Yb₂Si₂O₇) formed by reaction of added nano-Yb₂O₃ with SiO₂ not only restrained the crystallization of cristobalite, but also promoted densification of the materials by inhibiting grain growth of cristobalite. In addition, the addition of nano-Yb₂O₃ effectively decreased the expansion ratio of fused quartz ceramic materials during temperature elevating process by inhibiting crystallization of cristobalite, and the cold bending strength was slightly decreased due to the destruction of silicon-oxygen tetrahedron texture by addition of nano-Yb₂O₃.

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Heat capacities of 75SiO₂–6B₂O₃–10Al₂O₃–9MO (M=Mg,Ca, Sr and Ba) glasses and melts were determined between 345 and 1877 K by differential scanning calorimetry and drop calorimetry. The heat capacities of glasses and melts increase with increasing field strength of alkaline-earth metals. The glass transition takes place when the heat capacity of glass reaches 95–97% of Dulong-Petit harmonic limit. The configurational contribution to the melt heat capacity is about 20% and is independent of temperature. The partial molar heat capacity of B₂O₃ (Cp_B2O₃) in borosilicate melts containing alkaline-earth metals approaches to constant value (110–120 J·K⁻¹·mol⁻¹) above 1600 K and is consistent with heat capacity of pure B₂O₃ liquid. This suggests that there are no significant differences in coordination state of boron and in B–Si ordering among Mg, Ca, Sr and Ba-bearing alumino-borosilicate melts.

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Al doped ZnO (AZO) films were prepared on quartz substrates by the co-evaporation of ZnO and Al₂O₃ by EB-PVD. Structural, optical and electrical properties of AZO films were investigated, focusing on the effect of the electron beam power applied to the Al₂O₃ ingot. X-ray diffraction measurement showed that the AZO films were highly c-axis oriented. Transmittance of all the AZO films was over 85% in the visible range. The highest reflectance in the near IR range was obtained at the EB power on Al₂O₃ of 7.5 kW, 73% at 2500 nm. The lowest resistivity of 2.34 × 10⁻⁴ Ωcm was obtained for the film deposited with the EB power on Al₂O₃ of 7.5 kW.

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Since stillwellite-type ferroelectric LaBGeO₅ shows the intriguing physical properties by the doping/substituting-modification, the stillwellite-type glass-ceramics has been studied extensively from viewpoint of material engineering. In this study, we examined how the Nd-doping affects the glassy ferroelectric LaBGeO₅ and its modified sample, LaBSi_0.4Ge_0.6O₅. We experimentally demonstrated that small amount of the doping gives a significant effect on the crystallization and phase-separation trends.

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Optical, scintillation, and dosimeter properties of AlN ceramic were reported. AlN sample was SHAPAL, a commercial product of Tokuyama Corp. for mainly a heat sink application. From ultra violet to near infrared wavelengths, it showed 0.02–1% transmittance with visibly translucent appearance. In photoluminescence (PL), it exhibited mainly two emission bands around 340 and 550 nm with primary decay times of 0.92 and 0.24 ns, respectively. X-ray induced radioluminescence spectrum was investigated and 340 nm peak showed high emission intensity. As a dosimeter property, thermally stimulated luminescence (TSL) was studied and glow peaks appeared at 80 and 320°C. The linearity between the irradiated dose and TSL intensity was studied and AlN ceramic exhibited a good linear response from 0.002 to 0.1 Gy.

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Hydrogen-permselective amorphous silica membranes were synthesized by the counter diffusion chemical vapor deposition (CD-CVD) method using hexamethyldisiloxane as amorphous silica source, and the effect of the mesoporous intermediate layer and the CD-CVD process temperature on the hydrothermal stability of the amorphous silica membranes were studied. A mesoporous amorphous silica intermediate layer with a mean pore size of 20 nm was synthesized on a macroporous α-Al₂O₃ support. Under a hydrothermal condition at 500°C by maintaining steam-nitrogen mixed gas, the mesoporous amorphous silica intermediate layer exhibited an excellent stability, while the conventional sol gel-derived mesoporous γ-Al₂O₃ intermediate layer showed considerable degradation. The improvement in the hydrothermal stability at 500°C of the hydrogen-permselective amorphous silica membrane was successfully achieved by high-temperature synthesis at 700°C of the CD-CVD-derived microporous amorphous silica membrane on the porous α-Al₂O₃ support having the hydrothermally stable amorphous silica intermediate layer. Further study on the microstructure observations and evaluation of activation energies for the hydrogen permeation through the amorphous silica membranes were performed, and the results are shown and discussed from a viewpoint to achieve further hydrothermal stability improvement for further applications to hydrogen production processes.

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In this study, we have investigated the effects of heat-treatment condition and SiO₂ addition on the crystallization behavior and chemical durability of TiO₂–ZnO–B₂O₃–Al₂O₃ (TZBA) glass. Systematic analysis indicated that not only the precipitated phases (rutile, anatase, and brookite) after crystallization but also the chemical durability of TZBA glass-ceramics were affected by heat-treatment condition and SiO₂ addition. In a specific glass composition, we have found that etching resulted in TiO₂ grains of several dozen nanometers and asperity of several hundred nanometers at the sample surface. The present method, in which the increase of specific surface area and formation of nanoparticles at the surface is achieved by chemical etching, will become an important technique for the fabrication of novel bulk photocatalysts with high catalytic activity.

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We studied the diffusion of Zn in dense SnO₂ ceramics by using secondary ion mass spectrometry (SIMS). Dense SnO₂ ceramics with additives of 6 mol.% MgO and 0.2 mol.% Sb₂O₅ were synthesized, and Zn was implanted in the SnO₂ ceramics by ion implantation technique. The implanted samples were annealed at 850–1200°C, and the concentration profiles of Zn were evaluated by SIMS. The temperature dependence of Zn diffusion at 850–950°C could be expressed as D_Zn[cm²/s] = 3.3 × 10⁶ exp(−463.5[kJ/mol]/RT). These results in relation to the fabrication process of SnO₂ with added ZnO was then discussed.

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We investigated a multiple charge-injection mechanism of a magneto-electric (ME) capacitor. Although the capacitor showed a multi-step charge-injection process with regard to its capacitance–voltage (C–V) characteristics, the behaviors were found to be different depending on the tunneling layer thickness. Detailed analyses of current–voltage (I–V) characteristics revealed the presence of multi-step behavior in a sample exhibiting a Fowler–Nordheim (FN) tunneling mechanism. With decreases in the tunnel layer thickness, the FN tunneling behavior shifted to a high voltage region, at which point the multi-step behavior became unclear. These results indicate that the tunnel layer thickness plays an important role in this multi-step mechanism.

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Low-frequency Raman measurement was performed in alkali and alkaline-earth silicate glasses to elucidate the effect of introduction of network modifiers on boson peak nature. Our study illustrated that introduction of small/medium ions tended to increase in the boson peak frequency (ω_BP), whereas the introduction of large ions tended to decrease the frequency. Although ω_BP has been suggested to be proportional to the shear modulus, no linear relationship was obtained in these binary systems. Instead, we experimentally demonstrated that mean atomic volume can explain variations in ω_BP regardless of the trend of boson peaks.

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