Hydroxyapatite ceramics with oriented crystal structures are successfully fabricated via a novel and facile tape casting process of powder mixture system for the first time, during where a mixture of hydroxyapatite with altered particle size and morphology was utilized with a commercial acrylic polymer as binder. Followed by the lamination and sintering process, crystally oriented ceramic sheets of hydroxyapatite with micrometer thickness oriented along different axis were observed. The influence of powder composition and sintering temperature on the orientation degree and crystal structure change of the outermost surface of fabricated hydroxyapatite ceramic sheets was also elucidated in detail.

III–N-type (III = Al, Ga, and In) compounds are applied to various semiconductor and optical devices, such as LEDs and solar cells. Owing to their similar structures and electronic and electrical properties to those of III–N-type compounds, II–IV–N₂-compounds (II = Zn, Mg, and Mn; IV = Si, Ge, and Sn) are expected to become next-generation semiconductor materials. However, they possess low thermal stability, and their synthesis requires high-energy and complex processes that use high-pressure fields or high-vacuum environments. In this study, we investigated a new process to easily and quickly synthesize II–IV–N₂-compounds under ambient pressure using carbodiimide compounds and group 14 oxides as raw materials. The resulting ZnGeN₂ was successfully synthesized after heating a mixed powder of zinc carbodiimide and germanium oxide to 650–850 °C under a nitrogen atmosphere. In particular, zinc carbodiimide reacted with germanium oxide in the solid phase to produce ZnGeN₂, with CO₂ as a by-product. Thus, the high thermal stability of the generated CO₂ contributed to the reaction progressing at low temperatures, suggesting a mechanism similar to that of the solid-state metathesis reaction. When a mixed powder of zinc carbodiimide and silicon dioxide were heated to 850–1050 °C under a nitrogen atmosphere, ZnSiN₂ phase was successfully synthesized. The cyanogen and zinc vapors formed via the thermal decomposition of zinc carbodiimide contributed to its formation. We demonstrated that zinc carbodiimide functioned as an effective nitrogen and metal source to form ZnMN₂ (M = Si and Ge), although the reaction mechanisms of Si- and Ge-containing ZnMN₂ were different. Our proposed method is effective for the simple and rapid synthesis of ZnMN₂-type compounds from stable raw material systems. These characteristics are advantageous compared to the current complicated and time-consuming processes.

Thickly and densely sintered electrodes (TDSE) consisting of active materials can achieve highly capacitive Li-ion batteries and are one of the ideal electrode structures applicable for co-sintered-type solid-state batteries based on oxide-based solid electrolytes. This study focused on Li_3xLa_2/3−xTiO₃ (LLTO) as the TDSE for the anode. LLTO exhibits high Li-ion conductivity and a high capacity of 225 mAh g⁻¹ with an operation potential below 1 V (vs. Li⁺/Li). However, the electronic conductivity of LLTO is low (less than 10⁻⁸ S cm⁻¹), and the improved electronic conductivity seems necessary. In this paper, we investigated the electrochemical properties of LLTO sintered electrodes and improved the electronic conductivity of LLTO by Mn substitution for the Ti site. LLTO shows a huge overpotential during initial Li insertion due to low electronic conductivity of 1.1 × 10⁻⁹ S cm⁻¹, resulting in extremely low capacity. On the other hand, Mn substitution enhances the electronic conductivity, resulting in improved first-cycle charging properties.

In this study, LaF₃–LaOF:Yb³⁺/Tm³⁺ upconversion phosphors were synthesized using a solid-phase reaction method. In addition, their crystal structures and optical properties were analyzed. The crystal structure was analyzed using an X-ray diffractometer, revealing compositions of LaF₃ and LaOF in each sample. Photoluminescence characteristics were analyzed, and peaks were observed at approximately 480 nm (¹G₄→³H₆) and 800 nm (³H₄→³H₆). Analysis of the pump-power dependence of the photoluminescence intensity revealed that the slope of the peak near 480 nm (¹G₄→³H₆) was less than two, indicating the influence of thermal quenching. Finally, the temperature characteristics were analyzed, and the absolute and relative sensitivities were 0.0085 K⁻¹ and 0.69 % K⁻¹, respectively.

Metal decorations with gold- and platinum-like colors are widely used in ceramic products, particularly in the Western tableware industry. Tableware is typically decorated with thin metal films formed by the thermal decomposition of organometallic compounds called resinate. To be microwave-safe, decorative metal films should be insulated by forming an island-like structure of the metals; however, this often causes the loss of desired properties, such as elegant coloration and chemical durability. In this study, a platinum-colored decorative material was developed with a platinum-like color, sufficient alkali resistance, and microwavable insulation properties. The Pt-rich component is the key factor in achieving the insulated layer of which color is compatible with the non-insulated layer formed from Au-based resinate mixture for a standard platinum color. It was found that the addition of Rh resinate improved the coloration by suppressing the sintering of Pt particles. Zr was effective in improving the alkali resistance of the decorative thin films by depositing its oxide crystals in its glass matrix. It was found that a suitable design for the thermal decomposition procedure of the resinate has the potential to control the composition and structure of the metal films, which is useful for decorating tableware and as a method for creating functional films.

The relaxation behavior of nano silicon-graphite composite anode in lithium-ion half-cell just after the termination of lithiation has been investigated by the X-ray diffraction (XRD) method under argon atmosphere. The diffraction peaks of stage I of lithium graphite intercalation compound (Li-GIC) turned into those of stage II during the relaxation process, indicating that lithium-ions migrated from Li-GIC into Si toward the equilibrium lithium distribution between Li-GIC and Si side. While the amounts of lithium-ion migration were related to the amount of Si content in the anode, the rate constant depends on the charging current density.