We estimated site potentials for respective Li ions in the unit cell of Li₄SiO₄ crystal structure using the VESTA program and examined relation between the estimated site potentials and reactivity of the respective Li ions to CO₂. Values of the estimated site potentials for the respective Li ions were distributed over a range of the shallowest level (−11.6 V) to the deepest level (−17.3 V). It is forecasted that the depth of these potentials would relate with reaction between CO₂ and the respective Li ions in the unit cell of the Li₄SiO₄ crystal structure.

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Heterostructure Ag₃PO₄/Bi₂MoO₆ nanocomposites were synthesized by a deposition–precipitation method at high temperature and pressure. The as-synthesized products were characterized by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. In this research, cubic Ag₃PO₄ nanoparticles were deposited on orthorhombic Bi₂MoO₆ nanoplates. For 10.0 wt % Ag₃PO₄ loading, the Ag₃PO₄ nanoparticles with 5–10 nm in size were detected across the surface of Bi₂MoO₆ nanoplates. The effect of Ag₃PO₄ content on the photocatalytic properties was investigated by evaluating the degradation of rhodamine B under visible white light. The Ag₃PO₄/Bi₂MoO₆ nanocomposites exhibited more enhanced photocatalytic activity than the pure Bi₂MoO₆. Electron–hole diffusion in Ag₃PO₄/Bi₂MoO₆ nanocomposites and photodegradation mechanism of rhodamine B were also discussed in this report.

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The development of a fabrication process for sheet-type all-solid-state batteries with high energy density is critical for industrial applications. In this study, we systematically investigate the fabrication process of cells using composite positive electrode sheets with a high ratio of active materials. n-Decane was selected as a suitable solvent for the slurry because it has a sufficiently low vapor pressure and does not affect the ionic conductivity of solid electrolytes. In addition, the pre-densification of the composite positive electrode sheets was found to be effective in improving the cell performance. Suitable fabrication pressures were also determined. The cells fabricated under low-pressure conditions exhibited higher discharge capacities despite the higher internal resistance. Finally, our study revealed that the fracturing of LiNi_1/3Co_1/3Mn_1/3O₂ (NCM) occurs under high-pressure fabrication conditions because of the compression between the closely located NCM particles, resulting in the cleavage of the ionic and electronic conduction pathways.

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Bi_2−xZr_3x/4O₃ solid solutions were synthesized by conventional ceramic method and their color properties were investigated as environment-friendly inorganic orange pigments. Single phased Bi_2−xZr_3x/4O₃ solid solutions with tetragonal crystal structure are formed in the range of 0.3 ≤ x ≤ 0.5 compositions. Brilliant orange color powders were obtained for x = 0.5 composition heated at 800°C, which had color parameters (L*, a*, b*) of L* = 68, a* = 34, and b* = 69. The color of x = 0.5 samples is comparable to that of orange color specified in Japanese Industrial Standards (JIS) for a traffic paint. Since Bi_2−xZr_3x/4O₃ solid solutions are composed of nontoxic elements, it should be an alternative candidates to conventional PbCrO₄-based pigments for traffic paint.

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In this study, we successfully synthesized SrAlSiN₃:Ce³⁺ at 1073 K using the ammonothermal method. Scanning electron microscope images revealed bar-like crystals in the products. We investigated the effects of using a charge-compensating ion on the phosphor’s emission of SrAlSiN₃ with Ce³⁺ and Sr²⁺ and adding Na⁺ as a charge compensator. We found that Ce³⁺-doped SrAlSiN₃ exhibited a weak emission. However, SrAlSiN₃ co-doped with Ce³⁺ and Na⁺ exhibited a broad emission band centered at approximately 550 nm for an excitation wavelength of 460 nm. We, thus, found that Na⁺ has an important impact on Sr²⁺ and Ce³⁺ by acting as a charge-compensating ion. We were able to successfully synthesize a novel SrAlSiN₃:Ce³⁺ phosphor by adjusting the charge of Sr²⁺ and Ce³⁺ by controlling the Na⁺ co-doping.

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Graphite waste from primary batteries, active yeast and commercial rice husk ash have been used as pore-forming agents to fabricate porous alumina ceramics using a fugitive materials technique. The pore-forming agent ratios were between 10 to 50 wt %. The effects of the pore-forming agent ratios on the mechanical properties, the porosity and the microstructure have been investigated in this study. The results showed that through increasing the pore-forming agent ratio for graphite waste, yeast and rice husk ash, the porosity increased from 37.3 to 61.1%, 30.2 to 63.8% and 42.9 to 49.0%, respectively. The hardness also decreased from 172.6 to 38.1 HV₁ and from 160.6 to 15.0 HV₁ for porous alumina ceramics using graphite waste and yeast as pore-forming agents, respectively. However, the hardness of the porous alumina ceramics with rice husk ash as a pore-forming agent increased at 30 wt % (150.9 HV₁) and 50 wt % (158.9 HV₁). The tensile strength for porous alumina ceramics using graphite waste and yeast as pore-forming agents decreased from 24.9 to 14.3 MPa and from 26.2 to 5.4 MPa. The compressive strength decreased from 112.3 to 34.3 MPa and from 19.5 to 1.8 MPa, respectively. However, for porous alumina ceramics using rice husk ash, the tensile strength increased at 30 wt % (24.1 MPa) and 50 wt % (21.9 MPa). The compressive strength also increased at 30 wt % (69.7 MPa) and at 50% (60.1 MPa).

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The sintering of hardly sintered TiB₂ powder has been investigated using the spark plasma sintering (SPS) technique. The investigation revealed that TiB₂ powder can be sintered to highly dense bulk samples using SPS technique. However optimization of the sintering condition could not generate bulk samples with a fine microstructure. The addition of TiN was found to be effective in obtaining bulk samples with fine structure. Sample bending strength largely improved from 120 MPa for TiN free samples to more than 373 MPa, much higher than that of graphite, for TiN containing samples. The improvement in bending strength is attributed to the fine structure formed and to the strong bonding between TiB₂ and TiN particles.

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The effect of water vapor on the mechanical properties of a porous nickel/yttria-stabilized zirconia (Ni–YSZ) composite (volume ratio of Ni:YSZ = 40:60) was evaluated at 850°C, a typical operating temperature of a reversible solid oxide cell. Both the flexural strength and static fatigue limit of Ni–YSZ obtained from the static fatigue lifetime under a wet atmosphere (containing 4% H₂O) were lower than those under a dry atmosphere. This can be explained by absorption of H₂O molecules into YSZ particles, resulting in accelerated crack growth. The fatigue limit of Ni–YSZ was confirmed to be extremely low, corresponding to almost one-third of the flexural strength.

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The crossed-lamellar structure is known to exhibit a fantastic microarchitecture and excellent fracture resistance. Despite a similar morphology, this structure belongs to a family of homeomorphic microstructures with complex and varied crystallographies. In the present study, the crystallographies of different parts in Cymbiola nobilis shell were studied. The width of the first building blocks becomes increasingly thicker from the top to bottom of inner and middle layers. All the crystallites tend to align their c-axes towards the shell surface, and two twinned crystals share the c-axis at the top of inner and middle layers, while at the bottom the 001 pole figure shows two orientation components with c-axes inclined, and four preferential b-axis orientations distributed into two pairs. Texture analysis provides important information about the nature of shell growth, and suggests that the shape of the building blocks may be controlled by the crystallographic arrangement during the aragonite deposition.

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We prepared SrCuO₂ thin film by radio-frequency magnetron sputtering on glass substrate and have investigated its post-annealing effects on structure and thermal conductivity. The as-sputtered film belongs to two-dimensional spin system SrCuO₂, namely, layer-type SrCuO₂, which has a possibility of exhibiting high, anisotropic thermal conductivity by magnetic excitation of the spins. It was found that the as-sputtered film has (001)-orientation in which the spin layers are parallel to the surface of substrate and that post-annealing results in enhancement of crystallinity of the film such as disappearance of grain boundaries, which can cause an increase in thermal conductivity.

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Hybrid materials were prepared from ground glass powder and various zeolites such as A-type, mordenite, X-type, and Y-type zeolites, and their ion removal effect was investigated. The hybrid materials of A-type, Y-type, and mordenite zeolites showed similar Sr²⁺ removal rates from aqueous solutions. The removal rate of Sr²⁺ ions increased as the amount of zeolite in the hybrid materials increased. Compared with other hybrid materials, the hybrid materials of X-type zeolite showed higher Sr²⁺ removal rates, especially for zeolite content greater than 25%. As the amount of X-type zeolite in the hybrid materials increased, the Sr²⁺ removal rate increased greatly, with a 100% removal rate when the content of X-type zeolite exceeded 62.5%.

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Minor metals such as tungsten (W), molybdenum (Mo) and rhenium (Re) are necessary for high performance products, and a steady supply of them is very important. These metals are used for the X-ray target of the X-ray computed tomography equipment. In this study, we studied a dry separation method of W from discarded targets using the difference of volatilization behavior of the metal oxides. We obtained a 96% separation rate of W from the target by grinding, oxidation (1073 K, 5 h) and volatilization (1223 K, 5 h).

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