As an anniversary event of International Year of Glass (IYOG), especially to help advertisement of IYOG in Japan, we devoted ourselves for half a year of making a glass poster, called “Ikka-ni Ichimai [the annual S&T (Science and Technology) poster for everyone, in Japanese]”. The title of the poster is “GLASS - The most universal modern material”, and is already distributed, by Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT), to all over Japan from elementary to high school, and even university. The distribution is done to promote their interests for science and technology. The final products, the poster, the corresponding webpage, and the movies to explain how to enjoy the poster, are very much welcomed by many people including kids and students who do not major in glass. The poster shows how glass has been evolved by humankind, and how it supported human life to develop. We are quite confident that people can understand, by looking through this poster, how inevitable glass is, in various fields; from culture and art, medicine, science, and technology. Our hopes are to evoke interests of children to glass and material science, which, in a long term, help continuous evolution of glass for the future which supports the humankind.

Ancient Egyptian faience is a sintered quartz, usually with a blue-green glassy surface. Although its manufacturing method has been lost for about two thousand years, some descendants remained in the modern world, giving a clue to reconstructing the ancient technology. We now know that there are three distinct methods of faience making: efflorescence, cementation, and application. However, the study of faience has been mainly from the scientist’s point of view, not from the craftsman’s. This paper deals with replicating the ancient Egyptian faience from the creator’s viewpoint. The author proposes ways to manage the slumpy faience paste and improve its plasticity through experiments. Also, the experiments proved that the cementation method yields the best quality faience. The author also discovered that the surface glaze and bubbles differ in each method, and the difference can be observed by a low magnifying microscope. Such a handy means of examination will probably enlarge the possibility of examining valuable faience objects stored in museums. The outcome of the experiments tells that all three methods were present by the mid-Middle Kingdom Period, and the choice of a particular method might be based on the cost of manufacture.

Glasses and crystals from the same chemical system mostly share the same interatomic bond strength. Nevertheless, they differ by the arrangement of bonds in space, which gives birth to different atomic packing efficiencies. We show in this review that as far as the elastic moduli and hardness are concerned, the atomic packing density predominates over the bond strength. The shear modulus of a glass is usually much smaller than the one of the crystallized polymorphs, thanks to a more efficient packing of atoms in the latter. In contrast, the increase in hardness is quite limited, likely because of the additional contribution of dislocation activity to the deformation processes beneath the indenter in the case of crystals (shear plasticity). We also show that the occurrence of chemical heterogeneities (weak channels) at the mesoscopic scale in glasses, which is often associated with the lack of long range atomic ordering, promotes easy fracture paths and is responsible for the low toughness and fracture surface energy.

The advent of advanced quantum beam sources such as SPring-8 (synchrotron X-ray source) and J-PARC (spallation neutron source), which produce high-flux high-energy X-rays/neutrons, and advanced instrumentation techniques make it feasible to probe intermediate-range ordering in glasses and liquids. In particular, a combination of quantum-beam measurements and data-driven structure modelling assisted by advanced theory enables us to study both atomistic and electronic structures in glasses and liquids. In this article, recent state-of-the-art research studies on probing the order within disorder in oxide glasses and liquids are reviewed. Furthermore, the application of advanced topological analyses of glasses and liquids to uncovering the hidden ordering in the pairwise correlation is addressed.

Glass-ceramics have brought us necessary products for our modern society, such as heat-resistant tableware, biomaterials, electronics, photonics, and information technology. It has been more than 60 years since the invention of glass-ceramics, and even today, the research and development of characteristic glass-ceramics are ongoing. In particular, mechanical properties, thermal shock resistance, optical transparency, and ionic conductivity have always been important issues for glass researchers and the glass industry. This article reviews the fundamentals (materials and processes) and characteristic properties of modern glass-ceramics.

Materials with high ionic conductivity are attracting a great deal of attention because they are indispensable for improving the performance of batteries, sensors, and capacitors. Solid electrolytes, in particular, have a potential to compensate for the shortcomings of liquid electrolytes, and are the subject of intense research and development worldwide. One of the big characteristics of glass is its high formability. Here we are focusing on glass-electrolytes. Differences between “superionic conductive glasses” and “ordinary glasses”, as well as the mixed alkali effect will be overviewed. In addition, glasses can retain large residual stress inside that can reach the order of several GPa depending on the cooling conditions. These residual stresses also affect ionic conductivity. Recent results on the application of glass formability and softening fluidity to the formation of interfaces in all-solid-state batteries, and to ion emission from sharpened glasses are reviewed.

Optical communication fibers are one of the most important inventions of the glass product industry. These fibers are the only product made of glass to which the Nobel prize has been awarded. As an anniversary review for the International Year of Glass, we examine the evolution of communication fiber materials including multicomponent glasses, which were expected to replace silica glass. Owing to the difficulties in manufacturing low-loss fibers, multicomponent glasses, except fluoride glass, were dropped as the candidates for the core material. Pure silica glass is currently used as the core material for long-haul optical communication. As research on loss-reduction seems to have been stagnant for almost 40 years, a new method on loss reduction using hot compression is welcomed. While summarizing the history of glasses investigated for optical fibers, expectations for breakthroughs are discussed.

Over the last 20 years, many unconventional oxide glasses have been fabricated in bulk using a levitation technique. These glasses contain no or less network-former oxides; thus, they have been supposed not to vitrify so far. The levitation technique could vitrify them because the levitated melt was maintained without touching anything; thus, crystal nucleation was extremely suppressed. This review presents a brief introduction to the levitation technique. It also summarizes some functionalities that emerged in the glasses prepared using this technique, such as high refractive index, infrared transparency, strong luminescence, large magneto-optical effect, high elastic moduli, and crack resistance.

Sol–gel process is defined by IUPAC as “process through which a network is formed from solution by a progressive change of liquid precursor into a sol, to a gel, and in most cases finally to a dry network”. Among the many recent topics on sol–gel processing, the synthesis and applications of nonporous glasses and ceramics, aerogels, and mesoporous and/or nanostructured materials are briefly reviewed in terms of reaction mechanisms, process optimization, and functionalities.

Chalcogenide glass is a unique material applicable to infrared-transmitting optical elements that cover the atmospheric windows. It can be manufactured using molding technology, which provides mass productivity and high quality. Interest in chalcogenide glass research and developments has increased recently because of the rapid growth of the infrared optics market. This review summarizes the glass formation and properties of recently developed chalcogenide glasses. Selenium-based glasses which are widely used commercially have been introduced in comparison with infrared-transmitting crystals such as Ge and ZnSe. For sulfur-based glasses, glass-forming systems based on Ge–S and Ga–S have been described. These systems are completely free of arsenic and selenium, which are commonly used in conventional chalcogenide glasses. However, they provide glasses that are thermally stable against crystallization, and moldable. The typical spectral windows for Ge–S and Ga–S-based glasses have ranges of approximately 0.6–11 and 0.8–13 µm, respectively, although the short wavelength side strongly depends on the composition. Tellurium-based glasses are characterized by transmission in the far-infrared region, beyond 20 µm, and a refractive index higher than three. Recent studies on the temperature dependence of the viscosity and viscoelastic behaviors of chalcogenide glasses, which are both important for precision molding technology, are also discussed. Two characteristic structural relaxations have been observed in sulfide and selenide glasses.

The three research themes, fiber optics, upconversion, and biophotonics seem to be unconnected, but they can be actually connected. The author studied glass science in a glass laboratory when he was a student, and is currently conducting research on biophotonics using near-infrared light. This paper introduces the development of applications in different fields connected by basic science, starting from glass science and goaling to biophotonics.

The development of bioactive glasses, which began with the Hench’s invention of Bioglass^®, has considerably advanced over the past 20 years toward the creation of materials that not only chemically bond to living tissue, but also promote tissue regeneration. Some inorganic ions have the effect of stimulating cells and promoting biological functions, including bone formation. Glass-based materials have a significant advantage in the controlled release of inorganic ions because their compositions can be chosen systematically. Stimulating cells and improving therapeutic effects via the inclusion of various inorganic ions released from bioactive glass may represent a key strategy in the development of advanced biomaterials. This paper briefly reviews the research work related to bioactive glasses designed for tissue regeneration undertaken in the past two decades.

In general, glass has been recognized as an environmentally friendly material. However, the production of glass requires a lot of heat energy, and the raw materials also emit CO₂ at the melting process. In fact, commercial glasses are not easy to recycle. In glass industry of Japan, various efforts have been made so far to reduce the environmental impact of glass. In this paper, not only glass manufacturing technologies but also glass recycling technologies were reviewed, and the future glass production technologies to achieve carbon neutrality were also introduced.

The author and coworkers focused on the fabrication of composite photocatalysts and charge transfer between composite constituents for increased activity and sensitivity to visible light, aiming at developing materials for environmental preservation through the oxidative decomposition of organic pollutants and clean energy production through water splitting for hydrogen generation. Cu²⁺ ion-grafted titanium dioxide (TiO₂) was designed on the basis of visible-light-induced interfacial charge transfer from the valence band (VB) of TiO₂ to Cu²⁺, generating high oxidative decomposition activity owing to the utilization of photogenerated holes in the VB of TiO₂. Cu⁺ produced by electron injection was converted back to Cu²⁺ by oxygen (O₂) reduction through multi-electron O₂ reduction reaction. As for water splitting, zinc rhodium oxide (ZnRh₂O₄) and bismuth vanadate (Bi₄V₂O₁₁) as H₂ and O₂ evolution photocatalysts, respectively, were connected with silver (Ag), acting as a solid-state electron mediator, to prepare a composite photocatalyst that is sensitive to red light. The key function of the heterojunction photocatalyst is the transfer of photoexcited electrons from the conduction band (CB) of Bi₄V₂O₁₁ to the VB of ZnRh₂O₄ via Ag. Thus, the photoexcited electrons in the CB of ZnRh₂O₄ and the holes in the VB of Bi₄V₂O₁₁ effectively reduced and oxidized water, respectively, thereby splitting water and liberating H₂ and O₂ at a stoichiometric ratio.

Epitaxial films of (K,Na,Li)NbO₃ with 10 µm thickness and various Li contents were fabricated at 240 °C on (001)La:SrTiO₃ substrates by a hydrothermal method, and their crystal structures and piezoelectric properties were investigated. The film thickness was controlled by varying the deposition time (up to 3.5 h) and the number of deposition cycles. Scanning electron microscopy observations showed that dense thick films were formed. X-ray diffraction (XRD) measurements showed that {001}_c-oriented epitaxial films were deposited, and the out-of-plane lattice constant changed with an increase in the nominal composition A = [LiOH]/([KOH] + [NaOH] + [LiOH]) of the alkaline source solution. High-temperature XRD measurement revealed that with an increase in A, the Curie temperature increased, while the orthorhombic–tetragonal phase transition temperature decreased from 210 to 120 °C. These structural changes indicate that the Li content in the thick films can be controlled by varying A. The dielectric properties depend on the measurement frequency, and the minimum relative dielectric permittivity at all frequencies was observed at A = 0.02. Curves of field-induced strain vs. electric field showed that the maximum normalized strain of S_max/E_max = 40 pm/V was observed at A = 0.03, indicating that Li substitution is an effective way to improve the piezoelectricity of the hydrothermally deposited (K,Na)NbO₃ thick films. Interestingly, all thick films exhibited a piezoelectric response despite the applied electric field being lower than the coercive field. Moreover, the S_max/E_max value did not change significantly with an increasing applied electric field. These results suggest that the hydrothermally deposited (K,Na,Li)NbO₃ thick films adopt a self-polarized state without poling treatment.

Understanding the structure of disordered materials is still one of the most challenging topics in materials science because of insufficient structural information on experimental data. In this article, recent studies in solving the structure of glassy oxide materials via a combination of quantum beam experiments and computer simulations with the aid of advanced topological analyses are reviewed. To investigate glass structure on the intermediate length scale, three-dimensional atomistic structure models, which reproduce the multiple experimental dataset, were constructed. Furthermore, various topological analyses found that the network topology is an important structural feature for understanding properties of oxide glasses. The comprehensive approach including experimental, computational, and analytical method will be a promising way to probe the hidden order in disordered structure and provide crucial knowledge to design new glass materials with novel characteristics.

As the population ages worldwide, the importance of maintaining the metabolism of the skeletal system becomes increasingly important. The skeleton is the core of the locomotor and oral structure. Moreover, infection control is an essential part of orthopedic and oral surgery. This paper investigates new bone substitutes fabricated by the ionic substitution method leading to octacalcium phosphate (OCP) with excellent contact antibacterial ability, biocompatibility, and bone replacement. To improve the functionality of OCP-based materials as a bone substitute, we introduce a novel OCP block fabrication method based on the dissolution–precipitation method, study the factors that induce OCP in solution, and propose a robust method for cation substitution in the OCP unit lattice named the ionic insertion method. We then fabricate Ag-substituted OCP (OCP–Ag) blocks using this method and evaluate their antibacterial activity in vivo. These techniques will contribute to new-generation medical services and improve the quality of life of individuals requiring implants.

Point defects, dislocations, grain boundaries and interfaces are always involved in ceramic microstructures and play important roles for physical and chemical properties of ceramics. Currently, proper control of these crystal defects is inevitable to tailor ceramic materials with superior properties. This article reviews recent research projects on distinct properties and phenomena in ceramics due to crystal defects. In particular, we would like to emphasize importance of central core regions of crystal defects, namely, “crystal defect cores”. They have specific electronic and atomic structures that are different from those in bulk. Recent advances of nanoscale characterizations and theoretical calculations make it possible to acquire a variety of quantitative data on electronic structures enclosed at the crystal-defect cores, which gives clear understanding of various ceramic properties at the electronic and atomic levels.

The oxidation performance of silicon carbide (SiC) coating on nuclear fuel particle and the subsequent effect on the mechanical integrity was investigated. The effects of steam content on the phase composition and microstructure of the SiC layer at different temperatures were discussed. Reaction rates of steam with the SiC layer were found to obey the liner-parabolic oxidation law. The fracture strength of SiC shell was evaluated, which was dominated by the thickness variation of the SiC. Furthermore, finite element analysis was performed to simulate the stress distribution in the SiC shell during the crush test. The results revealed the SiC shell of reduced thickness caused by oxidation had higher stress concentration at the inner surface and resulted in a lower fracture strength value.

This paper discusses the hydrothermal synthesis of monodisperse oleate-capped iron oxide nanoparticles from an ammonia-treated Fe-oleate precursor solution. Nanoparticle samples synthesized at different temperatures were characterized using a combination of X-ray diffraction, Fourier-transform infrared spectroscopy, transmission electron microscopy, dynamic light scattering, vibrating sample magnetometry, and thermogravimetry-differential thermal analysis. This characterization revealed nanoparticles comprising inverse-spinel-type crystals covered by an oleate double-layer, with the saturation magnetization of the nanoparticles increasing with the temperature used for hydrothermal synthesis. Near-monodisperse nanoparticle distributions were obtained with hydrothermal reactions conducted at 150 °C.

Effect of thermal radiation on reliability is investigated for ZnO-based multilayer ceramic varistors (MLCVs). Withstanding capabilities against load dump surge (LDS) are compared between MLCVs with connecting structure of various-sized chips (co-MLCVs) and large size ones (5.7 × 5.0 × 3.0 mm). The LDS stability are improved with surface area of co-MLCVs. In particular, when connected chips are under 3.2 × 2.5 × 1.6 mm in size, co-MLCVs have more 30 % higher withstanding voltage (>100 V) and current (>53 A) than those of conventional large MLCVs, despite the same electrode area and nonlinear V-I characteristics. The results of thermal simulations show that heat dissipation in co-MLCVs is improved due to an expansion in surface area with a decrease of chip size. Thus, this notable enhancement of stability should be caused by an increase of heat radiation. And more, the LDS capability is independent of variation coefficient in V_1mA of chips (e.g., as σ/x < 0.032). It is evident that improvement of radiation performance gives a significant increase in reliability of MLCVs. The high thermal radiation certainly leads to further advance in MLCVs for high-energy surge.

Negative thermal expansion (NTE) in Bi_0.5+xNa_0.5−xVO₃ is investigated. The parent compound, Bi_0.5Na_0.5VO₃, is a lead-free polar perovskite oxide with a tetragonal distortion comparable to that of ferroelectric PbTiO₃ owing to the ordering of d_xy orbital of V⁴⁺ with d¹ electronic configuration. The c/a ratio was decreased by electron doping to V⁴⁺ through increasing Bi³⁺/Na⁺ ratio and transition to a non-polar cubic phase on heating accompanied by NTE with a large volume shrinkage of −2.28 % was enabled. It is found that the Bi_0.5Na_0.5VO₃ derivatives exhibit NTE when the c/a ratio is smaller than the critical value of ∼1.06.

In this study, we investigated the incorporation of 2D transition metal carbides and nitrides (MXenes) in glass materials. Ti₃C₂ MXene was successfully incorporated into borosilicate glass by spark plasma sintering. The addition of 1 vol % MXene nanoplatelets to the borosilicate glass resulted in them being homogenously distributed in the glass matrix. The addition of 2 vol % MXene nanoplatelets, however resulted in a coarser distribution. The fracture toughness of the glass samples with 0, 1 and 2 vol % MXene were 0.94, 1.36, and 1.21 MPa m^1/2, respectively. The enhanced fracture toughness of borosilicate glass with Ti₃C₂ MXene is ascribed to crack deflection, crack bridging, and pull-out of Ti₃C₂ MXene.

One dimensional heat transport model is formulated to solve melting rate of batch as well as unsteady temperature distribution in thickness direction of batch. Heat exchange of batch with decomposed gas, volumetric change of batch during melting and tide of foam are considered. Numerical simulation is performed to demonstrate the temperature distribution during both heating and melting period. The simulation also presents steady melting rate for foam thickness and response of the rate for tide of foam. The calculated result provides time-temperature history to estimate reaction path of batch and characteristics of rough melt.

AlN was succeeded to be synthesized at a low temperature of 900–1000 °C from the anhydrous aluminum chloride-melamine complex of a ratio of 1 to 3. To synthesize AlN at low temperature, four complexes were made from the anhydrous aluminum chloride with melamine, urea, hexamethylenetetramine, and aniline as ligands. The coordination state of the complex was confirmed by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). For the Al2p XPS spectra, a peak with higher binding energy emerged in the complex with melamine than the other complexes. For the N1s XPS spectra, the main peak with higher binding energy also can be detected, which indicates coordinated N to the Al atom. Consequently, the complex of AlCl₃ and three equivalents melamine showed a better coordination state than the others by FT-IR and XPS spectra. X-ray diffraction (XRD) patterns confirmed that the AlN phase forms for AlCl₃-equivalent melamine, -three equivalents melamine, and -three equivalents urea complex by heating at a low temperature of 900 and 1000 °C. Especially AlCl₃-three equivalents melamine complex can be converted to the AlN with relatively high crystallinity and fewer impurities due to its strong Al–N bonding on the triazine ring. The excess melamine due to the three equivalent amounts may work as reserve one which can provide to prevent a lack of melamine at high temperatures during AlN formation.

The tin–metal mixed hydroxides CaSn(OH)₆, MnSn(OH)₆, CoSn(OH)₆, and ZnSn(OH)₆, with cubic morphologies, were prepared using a coprecipitation method; they were subsequently transformed into the corresponding tin–metal mixed oxides by calcination at 600–900 °C. The crystalline structures and the morphologies of the various samples at each calcination step (just prepared, dried at 110 °C, and calcined at 600 and 900 °C) were systematically evaluated by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy, and X-ray absorption fine structure analyses. The cubic shapes of the CaSn(OH)₆ and ZnSn(OH)₆ nanoparticles were maintained after calcination of them at 600 and 900 °C, while those of MnSn(OH)₆ and CoSn(OH)₆ ones were not maintained after calcination of them.

Grinding is an important and widely applied industrial process for decreasing the size of particles, and it has been most frequently carried out together with liquid medium to improve the efficiency. In this study, the relationship among various grinding times of SiO₂ particles by rotating ball milling, volumes of ethanol used as the medium (corresponding to pendular to slurry states) and types of the liquid medium were systematically investigated in terms of the grinding efficiency. Without ethanol, the SiO₂ particles could never be pulverized even after 48 h of the ball milling, whereas they were pulverized in its presence because the ethanol adsorbed on the particle restricted their adhesion. The highest grinding efficiency was achieved with 1 ml of ethanol against 20 g of SiO₂ particles with polypropylene vessel including 200 g of zirconia balls with a diameter of 5 mm and seven zirconia balls with a diameter of 10 mm under 150 rpm for 24 h. The grinding efficiency increased with decreasing viscosity, because the impact power generated by the milling was efficiently conducted toward the particles due to its high flowability and low concentration in the impact zone. The ratio of the dipole moment to molecular volume in the liquid medium strongly affected the grinding efficiency, in which ethanol could efficiently serve as the medium, because they could easily adsorb to the SiO₂ particle. The overall grinding mechanism and process factors were investigated.

In the present study, simultaneous gross immobilization of radioactive Cs and Sr in zirconium phosphate was investigated by two methods. In the “dry method,” a mixture of HZr₂(PO₄)₃ with varying amounts of CsNO₃ and Sr(NO₃)₂ was heat-treated at 700 °C for 5 h to prepare Cs + Sr immobilized samples. At Cs + Sr immobilization of 0.3 + 0.15, the leaching amounts of Cs and Sr in 1 mol·dm⁻³ of HCl solution treated at 160 °C for 24 h were 2.9 × 10⁻⁴ g·m⁻² and 3.9 × 10⁻⁴ g·m⁻², respectively. In the “autoclave method,” aqueous solutions containing 0.5 and 0.25 mol of CsNO₃ and Sr(NO₃)₂, respectively, against 1 mol of (H₃O)Zr₂(PO₄)₃ were thermal-treated at 150–250 °C for 24 h to prepare Cs + Sr immobilized samples; immobilization of Cs and Sr was observed at 150 °C. The immobilized amount of Cs and Sr increased as the treated temperature increased, while the leaching amounts of Cs and Sr in 1 mol·dm⁻³ of HCl solution treated at 160 °C for 24 h decreased. The amount of immobilized Cs and Sr on (H₃O)Zr₂(PO₄)₃ at 250 °C were 0.30 and 0.20, and leaching amounts of Cs and Sr were 1.0 × 10⁻³ g·m⁻² and 1.4 × 10⁻³ g·m⁻², respectively.

ZnO nano- and microwires were grown on Si(111) substrates by mist chemical vapor deposition (mist-CVD). In 30 min of crystal growth, ZnO nanowires of approximately 100–500 nm diameters and 800–1000 nm length were grown. In 4 h of crystal growth, ZnO microwires were grown with some of them having a diameter and length of more than 2 and 9 µm, respectively. ZnO crystals grown for 30 min and for 4 h exhibited clear room-temperature photoluminescence (RT-PL) peaks near the band gap energy. Under high-optically pumped conditions, some ZnO microwires exhibited sharp peaks in RT-PL spectra, indicating that optically pumped lasing actions were obtained based on optical microcavities formed in a ZnO microwire.