Liquid-phase synthesis is a promising method for the production of Li₇P₂S₈I solid electrolytes. To improve the ionic conductivity of electrolytes developed via this method, this study focused on the separation of drying and crystallization processes for the precise control of crystallization at low temperatures. The pelletized samples exhibited a high ionic conductivity of approximately 1.0 mS cm⁻¹ when they were dried at temperatures below 90 °C under vacuum and crystallized at 110 °C. The separation of the drying and crystallization processes and pelletization before crystallization are crucial for achieving high ionic conductivities, comparable to those of materials obtained via solid-phase synthesis, at low temperatures.

Heating a mixture of α-Si₃N₄ and B₂O₃ at 2150 °C for 1 min under N₂ at a pressure of 0.85 MPa was found to generate β-Si₃N₄ plate whiskers with widths of ∼10 µm, thicknesses of ∼0.2 µm and lengths greater than 2 mm. Boron nitride powder, β-Si₃N₄ platelet grains and a small amount of α-SiC grains were also obtained. Single crystal X-ray diffraction demonstrated that the whiskers were elongated in the c-axis direction and additional tests indicated elastic deformation of the whiskers.

All-solid-state sodium secondary batteries have garnered significant attention as next-generation batteries with high safety. To realize an all-solid-state sodium secondary battery with a high energy density, it is necessary to develop a high-capacity electrode active material. In this study, we prepared amorphous molybdenum polysulfide (a-MoS_x, x = 3–7) using a mechanochemical process as electrode active material in all-solid-state cells using Na₃PS₄ sulfide electrolyte. In all-solid-state cells, a-MoS₃, a-MoS₄, a-MoS₅, a-MoS₆, and a-MoS₇ showed high reversible capacities of 260, 330, 470, 540, and 510 mAh g⁻¹, respectively. X-ray photoelectron spectroscopy analyses suggested that the discharge–charge reaction in a-MoS_x proceeds mainly by anion redox with dissociation and formation of disulfide bonds. Amorphous sulfur-rich MoS_x is thus a promising electrode active material with high capacity in all-solid-state sodium batteries.

Bizen stoneware is produced by firing shaped green clay in a firewood kiln at around 1200 °C. A purplish red color referred to as shiso happens to appear on the stoneware, but does not appear on the same stoneware heated in an electric furnace. Shiso was found to be caused by the formation of an approximately 0.5 µm thick hematite (α-Fe₂O₃) layer by reaction between the Bizen clay and K supplied from the firewood. Purplish red-colored samples similar to shiso Bizen were successfully prepared by annealing at 1100 °C for 2 h in air after heating the Bizen clay pellets with K₂CO₃ at 1230 °C in a gas mixture of 10 vol % CO and 90 vol % Ar.

Ultra- and nanofiltrations are utilized for the separation of polymers and proteins. In this study, we have investigated the application of the MgAl₂O₄ membrane produced by the aerosol deposition (AD) method for the separation of a polymer. A MgAl₂O₄ ultrafiltration membrane on the porous Al₂O₃ support layer was produced with intentionally leaving nano-sized pores instead of a completely dense membrane. The filtration performance was investigated by removing 1 million molecular-weight polyethylene oxide (PEO) from water, and the rejection rate with the AD MgAl₂O₄ on Al₂O₃ support to PEO was ∼44 % at the differential pressure of only ∼0.1 MPa, which was three times higher than our previous report by the dip-coating MgAl₂O₄ on Al₂O₃ of ∼14 %.

The Raman and infrared (IR) spectra for the alkali metaphosphate crystals composed of Q² units and the alkali pyrophosphate crystal composed of Q¹ units were assessed by density functional theory calculations. The assignments of peaks of the calculated Raman and IR spectra were consistent with reported assignments of phosphate crystals and glasses except for the assignment of the peaks around 1100 cm⁻¹ of the calculated IR spectra for the alkali metaphosphate crystals. Peaks around 1100 cm⁻¹ of IR spectra for phosphate crystals and glasses have been assigned to asymmetric stretching vibrations of bonds between phosphorus atoms and non-bridging oxygens (NBO) of Q¹ units. However, the calculated IR spectra showed that the peaks around 1100 cm⁻¹ result from not only asymmetric stretching vibrations of P–NBO bonds of Q¹ units but also symmetric stretching vibrations of P–NBO bonds and asymmetric stretching vibrations of –P–O–P– bonds of Q² units.

Shrinkage-rate control flash (SCF) sintering is an attractive flash sintering that is modified to densify ceramic green compacts up to high density, which controls electric current to keep shrinkage-rate constant by feedback from shrinkage behavior during a flash state. To build up easier sintering protocol and to realize faster shrinkage-rate, we attempted automated SCF-sintering using the predicted current profile without feedback of the shrinkage behavior. As results, 8YSZ polycrystal with a density of 5.83 g/cm³ and a grain size of 1.8–4.5 µm could be produced within 10 min during SCF and soaking regimes at the furnace temperature of 870 °C, although the linearity of shrinkage-rate during automated SCF-sintering is degraded from the assumed shrinkage-rate. In order to improve automated SCF-sintering further, a more accurate method of approximating the current profile would be necessary to realize the higher linearity of shrinkage-rate.