Coating solution of yttria-doped zirconia was prepared by using the sol–gel method and deposited on AISI 304 stainless steel substrates using dip-coating technique. The influence of the mechanical modification of stainless steel substrates and withdrawal rate on the coating quality has been studied. Herein, a novel method based on measuring the electrical capacitance of such coatings is developed in order to assess the coating quality. The method was performed on sanded and polished samples coated at various withdrawal rates, obtaining the greater thickness uniformity for the coatings deposited on polished specimens coated at a withdrawal rate of 25 mm·min⁻¹. The results obtained by the proposed method are well in agreement with those found by both optical and electron microscopies. Therefore, such a method seems to be of great interest because of its simplicity and low cost as compared to other well-established techniques, and its results may be a great support for them.

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The nitriding behavior of silicon/additives mixture with varied composition was investigated by focusing on the catalytic effect of sintering additives (Y₂O₃ and Al₂O₃) and diluents (Si₃N₄). While sintering additives have originally been mixed to form a liquid phase to promote both densification and grain growth during post-sintering, it was revealed that the addition of Y₂O₃ enhances the nitriding reaction by eliminating the SiO₂ and Si₃N₄ layer on the surface of silicon particles. Further, a synergistic effect resulting in an increased nitridation was verified by concurrent addition of sintering additives and diluents. The contribution of each component of the compact to the promoted nitriding reaction was elucidated in quasi in-situ manner by the combination of phase analysis and thermogravimetric analysis.

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The controlled assembly of micro- and nano-ceramic fillers in polymer nanocomposites provides robust properties such as wetting, adhesion, thermal conductivity, electrical insulation and optical activity, and enable the extended application of these hybrid materials as thermal interfacing materials in microelectronics and for energy conversion. However, the required properties can only be obtained either by homogeneous mixing or by anisotropic orientation of a large amount (>50 vol.%) of expensive fillers, which is economically inefficient. Here we propose a strategy for tuning the orientation and assembly of ceramic boron nitride nanofillers in a polymer nanocomposite using a small amount (<5 vol.%) of filler to enhance thermal conduction. The texture of the BN fillers is tuned by application of a nanosecond pulse electric field and a superconductor magnetic field (10 T); the three-dimensional structure of the products was analyzed using 3-D X-ray CT scanning. The enhanced anisotropic orientation and thermal properties of the products were assessed as a function of the structural variation of the boron nitride fillers in the polymer.

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For the purpose of use as anode active materials of lithium-ion secondary batteries, the group 14 elements (Si, Ge, Sn and Pb) and their oxides were investigated systematically. Ge(O_x) actually showed high capacity of around 1,200 mAh/g. This is corresponding to the fact that more than four moles of Li ions react to one mole of GeO_x. Except for SiO₂, the oxides of these elements generally showed relatively higher capacity and good cycle performance when compared to simple bodies. It is due to a conversion reaction to form Li₂O. Vinylene carbonate (VC) addition and capacity limitation were effective on improvement of cycle performance for not only Si but also other elements and oxides. A summation factor of irreversible capacity shows that the quantities of solid-electrolyte interface formation are almost same in the case of PbO₂-derived anode with/without the VC addition or the capacity limitation.

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High-quality (1 − x)(Mg_0.95Co_0.05)₂(Ti_0.95Sn_0.05)O₄–x(Ca_0.8Sm_0.4/3)TiO₃ ceramics were prepared by solid-state reaction. The products were characterized by scanning electron microscopy, X-ray diffraction, and network analyzer. (Mg_0.95Co_0.05)₂(Ti_0.95Sn_0.05)O₄ (MCTS) has a dielectric constant (ε_r) of ∼14.7, a high quality factor (Q×f) of ∼330,134 GHz, and a temperature coefficient of resonant frequency (τ_f) of ∼−46 ppm/°C. To produce a temperature-stable material, (Ca_0.8Sm_0.4/3)TiO₃ (CST) which has a large positive value τ_f of +400 ppm/°C, was added to MCTS. 0.84 MCTS–0.16CSTs an excellent combination of microwave dielectric properties: ε_r ∼ 22.5, Q×f ∼ 206,000 GHz (at 9 GHz), and τ_f ∼ −0 ppm/°C sinter at 1325°C, and can be utilized in the fabrication of microwave devices.

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Feasibility of high steam utilization operation with high current density in solid oxide electrolysis cells (SOECs) was investigated. Although higher reactant utilization leads to high efficiency and flexibility in SOEC systems, it increases the concentration polarization resistance, consequently decreasing the limiting current density, namely, decreasing the production rate of the energy carrier. To decrease the concentration polarization resistance, a porous structure-controlled NiO and Y₂O₃-stabilized ZrO₂ (YSZ) composite substrate prepared via an extrusion process was therefore used for a fuel electrode of an SOEC. After reduction of the fuel electrode, the porosity reached 54 vol.% and Ni, YSZ, and pores were uniformly distributed. In electrochemical measurements, the SOEC showed a high current density of 1.43 A cm⁻² at the thermo-neutral voltage at 800°C using a mixture of 20% steam in hydrogen (feed rate for excess supply). At high steam utilization of 90% and a resulting partial pressure of residual water of 0.02 atm, the SOEC could operate even at a high current density of 1.25 A cm⁻². The calculated concentration overpotential suggested that high steam utilization with high current density is feasible by using highly porous fuel electrodes.

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The reactivity of tellurite glass with Si₃N₄ was investigated using X-ray diffraction (XRD) analysis and was discussed in terms of basicity parameter, B, and the O1s binding energy, as a measure of the basicity of tellurite glasses. Through XRD analysis, it was revealed that tellurite glasses with a high basicity react significantly with Si₃N₄ to produce SiO₂. Observation of a Ag electrode containing glass and the microstructure of a Si wafer by scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) revealed that Ag paste containing highly reactive tellurite glass can effectively decompose the anti-reflection coating (ARC) composed of Si₃N₄. When glass with a high reactivity decomposed the ARC and the calcined Ag electrode contacts with the Si wafer, Ag/Te alloy particles were observed to precipitate from the tellurite glass phase at the interface between the Si wafer and Ag electrode. SEM and STEM observations also revealed that these Ag/Te alloy particles form a conductive path between the silicon wafer and Ag electrode.

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Calcium phosphate cements (CPCs) were prepared using meglumine to evaluate the effect of reduced mixing liquid in a CPC paste on plasticity and compressive strength. Raw CPC powders prepared using tetracalcium phosphate and dicalcium phosphate anhydrous were mixed with distilled water, meglumine aqueous solution (MG), and meglumine containing citric acid aqueous solution, to produce CPC pastes. Pastes prepared using MG exhibited a large plasticity, despite the fact that only a small amount of liquid was used for mixing the raw CPC powders (liquid-to-powder ratio of 0.21 g·g⁻¹). The compressive strengths and bulk densities of the CPC setting bodies increased with increasing MG concentration in the mixing liquid. CPC setting bodies prepared using 3 mass % MG had a compressive strength greater than 80 MPa after being soaked in simulated body fluid at 37°C for 24 h. The high obtained compressive strength was attributed to a reduced amount of (large) voids in the CPC setting body owing to efficient CPC powder dispersion in the mixing liquid during preparation of the CPC paste as a result of MG adsorbed onto the surface of the CPC powder. Although the setting time of CPC pastes prepared using MG was longer than that using distilled water because of the delay of hydroxyapatite formation with hydration, CPC pastes prepared using meglumine that contained citric acid aqueous solution had a shorter setting time. The resulting CPCs showed an improved performance for clinical application, that is, high compressive strength and adequate setting time.

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The sky-green glaze of ancient Jun ware was successfully imitated with the addition of 4 wt % calcium phosphate for introducing the phosphorus (P) to the composition. Effects of the calcium phosphate contents on the chromaticity, precipitated phase and microstructure of sky-green glaze were investigated. Based on the analysis of colorimeter, XRD, FT-IR, XPS and SEM, a possible coloring mechanism was proposed to explain the variation of glaze colors with the increasing of calcium phosphate content. The results indicated that the addition of calcium phosphate contributed to increasing the content of calcium iron phosphate [Ca₁₉Fe₂(PO₄)₁₄] and the size of phase separation droplets in glazes. The formation of Ca₁₉Fe₂(PO₄)₁₄ decreased the ratio of Fe²⁺ to Fe³⁺ and the increased size of phase separation droplets weakened the structural color, which increased the L* and b* value of glazes. Therefore, the color of sky-green glaze got more green and white gradually.

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Effects of PbCl₂ addition to perovskite CH₃NH₃PbI₃ precursor solutions on the photovoltaic properties were investigated. TiO₂/CH₃NH₃PbI_3−xCl_x-based photovoltaic devices were fabricated, and the microstructures of the devices were investigated by X-ray diffraction. The structure analysis indicated phase transformation of the perovskite structure from cubic to tetragonal system by chlorine (Cl)-doping. External and internal quantum efficiencies were improved by a small amount of Cl-doping, which resulted in improvement of the efficiencies of the devices. This would be due to preservation of the cubic CH₃NH₃PbI_3−xCl_x structure, and to expansion of energy gap and diffusion length of exitons by Cl-doping at the iodine sites.

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Preparation of a fluorescent ZnO/h-SiO₂ nanoparticle was proposed using Zn(OAc)₂ with NaOH. It exhibited a strong yellow emission. The key factor was micropores (1.45 nm) in the SiO₂ shell. The bandgap energy of the ZnO was higher (3.24 eV) than that of commercial ZnO. An XPS analysis indicated the formation of oxygen vacancies in the ZnO.

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Crystalline and amorphous TiS₃ active materials were prepared. The all-solid-state lithium secondary batteries with crystalline and amorphous TiS₃ showed the initial discharge capacity of about 560 mAh g⁻¹, corresponding to the theoretical capacity of TiS₃. However, the battery using crystalline TiS₃ had an irreversible capacity at the 1st cycle. The battery showed the reversible capacity of about 400 mAh g⁻¹ from the 2nd to 10th cycle. On the other hand, irreversible capacities were not observed for 10 cycles in the battery with amorphous TiS₃. The structural changes of crystalline and amorphous TiS₃ were observed by XRD and HR-TEM during cycling. Crystalline TiS₃ became partially amorphous during the cycling. Amorphous TiS₃ maintained amorphous state for 10 cycles and thus had the better cyclability compared to crystalline TiS₃.

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High basicity glass-ceramics were synthesized from mainly steel slag using single-stage sintering method. The proportion of steel slag used in glass batch was 85 wt % of the total batch mixture. The preparation and crystallization behavior of steel slag-derived glass-ceramics were investigated using differential thermal analysis (DTA), physical and mechanical properties, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The crystallization of the glass is controlled by surface crystallization mechanism. The morphology of the crystals developed from ultrafine particles to lamellar and irregular granular crystals with the increasing of the heat treating temperature. Wallostonite (CaSiO₃) with the lamellar shape and diopsite (CaMgSi₂O₆) with irregular granular shape are the major phases in the glass-ceramics heat treated between 1000 to 1200°C, while akermanite (Ca₂MgSi₂O₇) phase disappeared. The optical properties of glass-ceramics were achieved while heat treated at 1150°C for 60 min: high linear shrinkage of 5.7% and high bending strength of 58.7 MPa.

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MgO nanowires were synthesized by an unique thermal evaporation technique employing solar energy at atmospheric pressure in air. In the conventional thermal evaporation technique, electrical furnace was heated to high temperatures and kept for a long time at the high temperatures for vaporizing source materials. Thus the significant amount of electric energy is consumed. However in the present method, solar thermal energy instead of electricity was used as the heat source for the evaporation of metal precursor. Sunlight was focused on the Mg powder through a magnifying lens to concentrate solar thermal energy. The concentrated solar energy created heat enough to vaporize the Mg powder. Then the Mg vapor reacted with oxygen in air to form MgO nanowires. Furthermore, the MgO nanowires were synthesized within a few seconds, which indicates that this method has also an advantage of synthesizing rapidly MgO nanowires.

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Er³⁺–Yb³⁺ co-doped CaO–WO₃–SiO₂–B₂O₃–NaF glass ceramics containing CaWO₄ crystals were prepared by the melt-quench and crystallization method. The luminescence effect of the glass ceramic sample which was maintained for 70 min at 750°C exhibited the highest emission peak intensity in this work. As the crystallization time increased, the amount and the size of crystals increased and the crystal shape transformed from sphere to irregular polyhedron. Green and red up-conversion light appeared in the glass ceramics excited by 980 nm. Two emission peaks of green band at 525 and 545 nm correspond to ²H_11/2→⁴I_15/2 and ⁴S_3/2→⁴I_15/2 energy transitions of Er³⁺ ions and red band emission peak at 655 nm is correspond to ⁴F_9/2→⁴I_15/2 energy transitions of Er³⁺ ions. The up-conversion mechanism of Er³⁺–Yb³⁺ doped glass ceramics were investigated and the effect of excitation power on green and red light was analyzed. The up-conversion fluorescence intensity of the glass ceramics is the highest when the content of Er₂O₃ is 0.5 wt % and the content of Yb₂O₃ is 4.5 wt %.

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