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The paper presents room-temperature magnetoresistance in molecular spintronic nanodevices fabricated using magnetic thin-film edges.

In this study, the effect of GeO2 on the thermal stability and proton mobility (μH) of proton-conducting phosphate glasses was experimentally investigated using 22HO1/2–3NaO1/2–(12 − x)LaO3/2–xGeO2–63PO5/2 glasses. Increasing glass transition temperature (Tg) and μH at Tg were experimentally found out, when LaO3/2 was substituted with GeO2, and this behavior coincides well with the prediction obtained from a linear regression model previously proposed. Based on the glass structure and nature of a P–O bond, both enhanced Tg and μH at Tg were strongly related to the formation of heteroatomic P–O–Ge linkages. The Ge atoms are six-fold coordinated with O atoms, and they tightly bridge the (PO3−)n phosphate chains through the heteroatomic P–O–Ge linkages, resulting in rigid phosphate frameworks with higher Tg. The formation of the heteroatomic P–O–Ge linkage results in increased covalency in the P–O bond. This increases the ionicity of the O–H bond owing to the balanced electron transfer to prevent excessive decrease in electron density on the O atom in the P–O–H bond. Thus, μH at Tg increases because the increasing ionicity weakens the O–H bond. Herein, the increasing covalency in the P–O bond is discussed according to the difference in the electronegativity and atomic orbitals that contribute to the bond with an O atom between La⋯O and Ge–O bonds.

Recent studies on nanopillar arrays, one type of nanofluidic device, have demonstrated various tools for bioanalysis. When carrying out nanopillar array-based separation, it is indispensable to obs...

Ultra-thin proton-conducting phosphate glass was fabricated by press-forming at high temperature. The glass was evaluated for its ohmic loss reduction when installed as an electrolyte in intermediate-temperature fuel cells. The 36HO1/2 4NbO5/2 2BaO 4LaO3/2 4GeO2 1BO3/2 49PO5/2 glass (36H-glass) was prepared by alkali-proton substitution. Herein, 3–4 mg of 36H-glass was placed onto a 50 μm-thick stainless steel or Pd support and then sandwiched by a glassy carbon plate, whereupon a 600 kg load was applied at temperatures varying as 333–391 °C. Ultra-thin 36H-glass with a thickness of 16 μm was successfully obtained without degradation of proton conductivity. A fuel cell incorporating the Pd-supported ultra-thin 36H-glass was successfully operated at 300 °C, and the ohmic loss of the fuel cell was reduced down to 2.7 Ω cm2 from the previous reported value of several tens of Ω·cm2.

Anhydrous silicophosphoric acid glass with an approximate composition of H 5 Si 2 P 10 O 32 was synthesized and its thermal and proton-conducting properties were characterized. Despite exhibiting a glass transition at 192 °C, the supercooled liquid could be handled as a solid up to 280 °C owing to its high viscosity. The glass and its melt exhibited proton conduction with a proton transport number of ~1. Although covalent O-H bonds were weakened by relatively strong hydrogen bonding, the proton conductivity (4 × 10 -4 S cm -1 at 276 °C) was considerably lower than that of phosphoric acid. The high viscosity of the melt was due the tight cross-linking of phosphate ion chains by six-fold-coordinated Si atoms. The low proton conductivity was attributed to the trapping of positively charged proton carriers around anionic SiO 6 units (expressed as (SiO 6/2 ) 2- ) to compensate for the negative charges.

Na-free Si clathrates consisting only of Si cages are an allotrope of diamond-structured Si. This material is promising for various device applications, such as next-generation photovoltaics. The probable technique for synthesizing Na-free Si clathrates is to extract Na+ from the Si cages of Na24Si136. Vacuum annealing is presently a well-known conventional and effective approach for extracting Na. However, this study demonstrates that Na+ cannot be extracted from the surface of a single-crystalline type-II metallic Si clathrate (Na24Si136) in areas deeper than 150 mu m. Therefore, a novel method is developed to control anisotropic ion diffusion: this is effective for various compounds with a large difference in the bonding strength between their constituent elements, such as Na24Si136 composed of covalent Si cages and weakly trapped Na+. By skillfully exploiting the difference in the chemical potentials as a driving force, Na+ is homogeneously extracted regardless of the size of the single crystal while maintaining high crystallinity. Additionally, the proposed point defect model is evaluated via density functional theory, and the migration of Na+ between the Si cages is explained. It is expected that the developed experimental and computational techniques would significantly advance material design for synthesizing thermodynamically metastable materials.

The effects of heating temperature in ultraviolet irradiation process (hereafter named as UV temperature) on photon-activated precursor YBa2Cu3O7- x (YBCO) films were investigated systemically. The results from FT-IR spectra, carbon content, the XPS spectra of Cu 2p and O1s reflected that the photochemical reactions were inhibited by high UV temperature. And we proposed a model to analyze and explain the mechanism of how the UV temperature affect the photochemical reactions. Finally, the YBCO films irradiated at 100 or 150 °C had higher Jc values (about 7.0 MA/cm2 at 77 K and 0 T) than samples UV-irradiated under high UV temperatures (beyond 200 °C), which showed lower Jc values due to the weakening of oxidation progress. Consequently, a temperature window of 100–150 °C in UV irradiation process maybe suitable for the deep UV irradiation method used in YBCO preparation.

In this study, a proton conducting phosphate glass, which was fabricated by alkali-proton substitution, was clearly demonstrated to transport protons over a wide oxygen partial pressure in air and hydrogen atmospheres, and in both dry and wet conditions. The proton transport number was confirmed to be unity, regardless of whether the glass was exposed to air or hydrogen atmospheres, in both hydrogen concentration and water vapor concentration cells. The dry hydrogen can be formed by electrochemical hydrogen pumping without current leakage as a result of the presence of other charge carriers. These properties derive from a proton incorporation mechanism, which is non-dependent on defect equilibria, unlike acceptor-doped perovskite-type proton conducting oxides. The advantages of applying this proton conducting glass electrolyte to fuel cells and steam electrolysis is also discussed.

The models to describe the proton mobility (μH) together with the glass transition temperature (Tg) of proton conducting phosphate glasses employing the glass composition as descriptors have been developed using a statical analysis approach. According to the models, the effects of additional HO1/2, MgO, BaO, LaO3/2, WO3, NbO5/2, BO3/2 and GeO2 as alternative to PO5/2 were found as following. μH at Tg is determined first by concentrations of HO1/2 and PO5/2, and μH at Tg increases with increasing HO1/2 concentration and decreasing PO5/2. The component oxides are categorized into three groups according to the effects on μH at Tg and Tg. The group 1 oxides increase μH at Tg and decrease Tg, and HO1/2, MgO, BaO and LaO3/2 and BO3/2 are involved in this group. The group 2 oxides increase both μH at Tg and Tg, and WO3 and GeO2 are involved in this group. The group 3 oxides increase Tg but do not vary μH at Tg. Only NbO5/2 falls into the group 3 among the oxides examined in this study. The origin of the effect of respective oxide groups on μH at Tg and Tg were discussed.

Mechanoresponsive diacetylenes (DAs) exhibiting a transition of crystalline orientation from light-inert to light-active state upon applied force are reported. Amide units are introduced to DAs where hydrogen bonding is utilized to control intermolecular interactions. Application of external pressure (2-150 MPa) to DAs results in an emergence of new crystal phases with changing the d-spacing which possibly reduces the reaction barrier. Accordingly, the dramatic crystalline transition from "perfectly off" to "on" state to undergo the light-induced topochemical polymerization of bulk DA crystals is obtained. Subsequent UV irradiation at a wavelength of 254 nm enables the polymerization of the pressed region, changing its color from white to blue which suggests the selective formation of polydiacetylene (PDA) polymorphs. In addition, by utilizing the mechanoresponsive crystallinity with low-enough activation pressure, a new strategy for PDA patterning is demonstrated based on the selective transfer of information by means of force to a DA film. This phenomenon can be applicable to a new nanoimprinting technique where no mechanical deformation of resist materials but phase transition is induced by the mold.

The temperature dependence of proton conductivity in 36HO1/2−4NbO5/2−2BaO-4LaO3/2−4GeO2−1BO3/2−49PO5/2 glasses prepared through the alkali-proton substitution method was investigated in this study. The activation energy of proton conduction, E a , was found to exhibit an non-Arrhenius type temperature dependence. The origin of the temperature dependence of the proton conductivity caused by thermal expansion of the glass structure was discussed in terms of the effect of changes in the local environment surrounding the protons. These changes were elucidated using Raman spectroscopy, 1H- and 31P-NMR, infrared spectroscopy, and molecular modeling. Because protons form O-H bonds, they are sensitive to changes in the distance between two oxygen atoms, which affects the strength of the hydrogen bond, and concluded that there is a temperature dependence as observed.

Sodium ions in 25NaO 1/2 -6LaO 3/2 -6GeO 2 -63PO 5/2 (mol%) glasses were substituted with protons using corona discharge treatment (CDT) under a H 2 atmosphere. The substitution of sodium ion to proton proceeded from the anode side to the cathode side with constant current flow during the CDT. A crystalline free and transparent glass plate of 0.3 mm thickness was obtained after CDT for 96 h. The maximum decrease rate from sodium ion to proton was 78 ± 10%. The proton conductivity of 8.5 × 10 −4 S/cm was attained at 400 °C.

A working hypothesis to design proton-conducting phosphate glasses exhibiting high proton conductivity and high stability was proposed. In this hypothesis, the precursor glass before electrochemical alkali-proton substitution (APS) is required to fulfill the terms of (i) the concentration of NaO1/2 in the precursor glass needs to be higher than 35 mol%, (ii) the O/P ratio of the glass composition cannot exceed 3.5, (iii) the glass network modifier oxides need to consist of cations with low electronegativity, (iv) the glass must contain a sufficient amount of glass network modifiers and intermediate oxides, such as alkaline-earth oxides, Al2O3, Y2O3, La2O3, WO3, Nb2O5, and Ta2O5, (v) the glass needs to consist of more than four or five components, and (vi) the glass must contain a small amount of GeO2 and/or B2O3. Based on the proposed working hypothesis, we obtained a 36HO1/2–4NbO5/2–2BaO–4LaO3/2–4GeO2–1BO3/2–49PO5/2 glass (36H-glass) by APS. While the glass transition temperature of 36H-glass was 179 °C, the glass, accurately the super cooled liquid, was stable for a long time up to 280 °C under fuel cell operating conditions and exhibited 1 × 10−3 S cm−1 at 280 °C, indicating that the developed working hypothesis is useful to design new proton-conducting electrolytes that work at intermediate temperatures.

The development of an unconventional synthesis method has a large potential to drastically advance materials science. In this research, a new synthesis method based on a solid-state electrochemical reaction was demonstrated, which can be made available for intercalation and ion substitution. It was referred to as proton-driven ion introduction (PDII). The protons generated by the electrolytic dissociation of hydrogen drive other monovalent cations along a high electric field in the solid state. Utilizing this mechanism, Li+, Na+, K+, Cu+, and Ag+ were intercalated into a layered TaS2 single crystal while maintaining high crystallinity. This liquid-free process of ion introduction allows the application of high voltage around several kilovolts to the sample. Such a high electric field strongly accelerates ion substitution. Actually, compared to conventional solid-state reaction, PDII introduced 15 times the amount of K into Na super ionic conductor (NASICON)-structured Na3–xKxV2(PO4)3. The obtained materia...

The sodium ions in Na3Zr2Si2PO12 (NASICON) were substituted with protons using an electrochemical alkali–proton substitution (APS) technique at 400 °C under a 5% H2/95% N2 atmosphere. The sodium ions in NASICON were successfully substituted with protons to a depth of

YBa2Cu3O7−x (YBCO) thin films (with thickness of 220–230 nm) and thick films (with thickness of 1.1–1.2 µm) were prepared using low fluorine solutions with different F/Ba ratios (F/Ba=1–4.5). The effect of F/Ba ratio on the properties of the films was systematically investigated. The results showed that films derived from solutions with F/Ba 2 solutions, the formation of BaF2/BaOF phase was retarded by the decomposition of Ba1−xYxF2+x (BYF) intermediate phase. We also found that extra fluorine in the solution resulted in a large number of impurities and a-axis grains in the thick films, degrading the film superconductivity. F/Ba=2 was the optimal ratio in the solution to fabricate high-Jc YBCO thick films.

Magnetocapacitance (MC) effect, observed in a wide range of materials and devices, such as multiferroic materials and spintronic devices, has received considerable attention due to its interesting physical properties and practical applications. A normal MC effect exhibits a higher capacitance when spins in the electrodes are parallel to each other and a lower capacitance when spins are antiparallel. Here we report an inverse tunnel magnetocapacitance (TMC) effect for the first time in Fe/AlOx/Fe3O4 magnetic tunnel junctions (MTJs). The inverse TMC reaches up to 11.4% at room temperature and the robustness of spin polarization is revealed in the bias dependence of the inverse TMC. Excellent agreement between theory and experiment is achieved for the entire applied frequency range and the wide bipolar bias regions using Debye-Fröhlich model (combined with the Zhang formula and parabolic barrier approximation) and spin-dependent drift-diffusion model. Furthermore, our theoretical calculations predict that the inverse TMC effect could potentially reach 150% in MTJs with a positive and negative spin polarization of 65% and −42%, respectively. These theoretical and experimental findings provide a new insight into both static and dynamic spin-dependent transports. They will open up broader opportunities for device applications, such as magnetic logic circuits and multi-valued memory devices.

The proton transport properties of 32 kinds of proton-conducting phosphate glasses with broad ranges of glass transition temperature, proton conductivity, and the proton carrier concentration were studied. Almost constant proton mobility of around 2 × 10−8 cm2 V−1 s−1 at the glass transition temperature, corresponding to a diffusion coefficient of approximately 4 × 10−10 cm2 s−1, was found for the glasses. The reason why the diffusion coefficient of protons is almost constant in various proton-conducting phosphate glasses was discussed based on the role of the protons as a cross-linker within the phosphate framework via hydrogen bonding. We evaluated the highest proton conductivity of the phosphate glasses and melts based on the almost constant mobility at their glass transition temperatures and obtained a highest expected proton conductivity of 7.5 × 10−3 S cm−1 at 300 °C. The potential of proton-conducting phosphate glasses as electrolytes in intermediate temperature fuel cells was also discussed.

Trilayer films of YBa2Cu3 O 7−x (YBCO)/Y2 O 3/ YBCO were prepared on LaAlO3 (100) single-crystal substrates using sol-gel method. The results indicated that both the YBCO and the Y2 O 3 films in the trilayer exhibited remarkable biaxial texture characteristics. The epitaxial relationship between the Y2 O 3 and YBCO films was Y2 O 3∥ YBCO, Y2 O 3∥ YBCO, and the interface of both films was well-defined. The top and bottom YBCO layers in the trilayer exhibited zero resistance at 88 K. When the nominal thickness of the Y2 O 3 interlayer in the trilayer was 180 nm, the V − I curve was linear, and the resistivity between the two YBCO layers was 2.5 × 106 Ω cm. These results demonstrated that YBCO/Y2 O 3/YBCO trilayer could be realized using the sol-gel method, which is inexpensive and easy to scale up.

La2Zr2O7 (LZO) films and CeO2/LZO composite films were prepared on the biaxially textured NiW tapes using metal organic deposition method. Effect of molar ratio of La/Zr in the precursor solution on the texture and surface morphology of LZO films and composite CeO2/LZO films was investigated systemically. It was found that the content of lanthanum played an important role in the orientation control of the LZO film. Finally, the LZO film with ratio of La/Zr = 1.1/1 was obtained with the best properties as compared to others. And highly textured LZO-11 and CeO2/LZO-11 films with smooth surface were obtained on the NiW tape. YBa2Cu3O7-x (YBCO) films with enhanced critical current density (Jc) were obtained on the optimized CeO2/LZO buffer layer. The LZO films were prepared from different LZO solutions with different molar ratio of La/Zr, and the effects of the La/Zr ratio on the texture and surface morphology of LZO films were systemically investigated. The results confirmed that the content of lanthanum in solution was closely related to the orientation control of the LZO film. When the ratio of La/Zr was smaller than La/Zr = 1, the pure (l00)-oriented phase was not achieved. When that was larger than La/Zr = 1.2, in spite of the pure (l00)-oriented phase, the more lanthanum content increased the lattice parameter of the LZO films. In summary, the ratio of La/Zr = 1.1 was the optimized ratio for the fabrication of LZO film due to the best texture and surface morphology.

In this work, the effect of alkaline-earth species used in phosphate glasses on the mobility of proton carriers was investigated. Initially, 35NaO1/2–5RO–3NbO5/2–3LaO3/2–2GeO2–2BO3/2–50PO5/2 (R: Mg and Ba) glasses were subjected to the electrochemical substitution of Na+ ions with H+ at intermediate temperatures, producing proton conductors with high proton carrier concentrations (>8 × 1021 cm−3). The mobility of the proton carriers in the Ba glass was higher than that in the Mg glass. We studied the origin of this phenomenon in terms of the O–H and P–O bonding features using infrared spectroscopy and X-ray photoelectron spectroscopy, respectively. The higher mobility of proton carriers in Ba glass was attributed to weaker O–H bonding, which originated from the highly ionic character of Ba–O bonding compared with the comparatively covalent Mg–O bonding. Our findings indicate that a higher mobility of proton carriers can be achieved for glasses containing less electronegative glass network modifiers. The application of this strategy would be beneficial for the development of proton-conducting glass electrolytes for intermediate-temperature fuel cells.

We investigate the structural and magnetic properties of Ni 78 Fe 22 thin films sandwiched between low-softening-point (LSP) glasses, which can be used in spin quantum cross (SQC) devices utilizing stray magnetic fields generated from magnetic thin-film edges. We also calculate the stray magnetic field generated between the two edges of Ni 78 Fe 22 thin-film electrodes in SQC devices and discuss the applicability to spin-filter devices. Using the established fabrication technique, we successfully demonstrate the formation of LSP-glass/Ni 78 Fe 22 /LSP-glass structures with smooth and clear interfaces. The coercivity of the Ni 78 Fe 22 thin films is enhanced from 0.9 to 103 Oe by increasing the applied pressure from 0 to 1.0 MPa in the thermal pressing process. According to the random anisotropy model, the enhancement of the coercivity is attributed to the increase in the crystal grain size. The stray magnetic field is also uniformly generated from the Ni 78 Fe 22 thin-film edge in the direction perpendicular to the cross section of the LSP-glass/Ni 78 Fe 22 /LSP-glass structures. Theoretical calculation reveals that a high stray field of approximately 5 kOe is generated when the distance between two edges of the Ni 78 Fe 22 thin-film electrodes is less than 5 nm and the thickness of Ni 78 Fe 22 is greater than 20 nm. These experimental and calculation results indicate that Ni 78 Fe 22 thin films sandwiched between LSP glasses are useful as electrodes for SQC devices, serving as spin-filter devices.

One dimensional pattern of 500 nm period was formed on a soda-lime silicate glass by the electrical nanoimprint below the glass transition temperature. The imprinted glass surface was analyzed using a transmission electron microscopy and an energy-dispersive X-ray spectroscopy with the cryogenic system. The concentrated parabolic layers of Ca 2 + and Mg 2 + were formed separately in the Na + deficient layer. The deficient area both of such alkali and alkaline-earth cations was preferentially removed in an alkali etchant, resulting the enhancement of the aspect ratio of the one-dimensional relief pattern. Therefore, the distribution control of alkaline-earth cations was important for the fabrication of sub-micron scale patterns with high aspect ratio on the glass surface.

X-ray photoelectron spectroscopy with C 60 -ion sputtering (C 60 -XPS) and electron spin resonance (ESR) revealed the migration behavior of network-modifier cations in an electrically poled soda-lime silicate glass. The Na + -deficient layer of 700-nm thickness was confirmed at the anode side surface. The Mg 2 + and Ca 2 + existed in the 200-nm thick layer from the top surface were concentrated in the layer of 200–700 nm depth from the surface. Additionally the oxygen content in the 200-nm thick layer decreased by the degassing as oxygen molecules from the glass surface, which is an essential requirement for the migration of Mg 2 + and Ca 2 + to cathode side. The bond scission between Si–O–Si is caused by the concentrated Mg 2 + and Ca 2 + , resulting the formation of SiO − (Mg 2 + or Ca 2 + ) − OSi and Si· (Si E′ center). We have also confirmed the generation of oxygen hole center (NBOHC) and peroxy radical (POR) in the electrically poled soda-lime silicate glass.

A novel superconductor, LaPt5As, which exhibits a new crystal structure was discovered by high-pressure synthesis using a Kawai-type apparatus. A superconducting transition temperature was observed at 2.6 K. Depending on the sintering pressure, LaPt5As has superconducting and non-superconducting phases with different crystal structures. A sintering pressure of around 10 GPa is effective to form single-phase superconducting LaPt5As. This material has a very unique crystal structure with an extremely long c lattice parameter of over 60 Å and corner-sharing tetrahedrons composed of network-like Pt layers. Density functional theory calculations have suggested that the superconducting current flows through these Pt layers. Also, this unique layered structure characteristic of LaPt5As is thought to play a key role in the emergence of superconductivity. Furthermore, due to a stacking structure which makes up layers, various structural modifications for the LaPt5As family are conceivable. Since such a high-pressure synthesis using a Kawai-type apparatus is not common in the field of materials science, there is large room for further exploration of unknown phases which are induced by high pressure in various materials.

Using Raman and 31 P magic-angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopies, we studied the structural changes in 35NaO 1/2 -1WO 3 -8NbO 5/2 -5LaO 3/2 -51PO 5/2 glass upon introducing Al 2 O 3 and/or Y 2 O 3 in order to understand the reduced mobility of proton carriers in glasses with Al 2 O 3 and/or Y 2 O 3 in which proton carriers were injected by alkali-proton substitution (APS). The Raman and 31 P MAS-NMR spectra showed that phosphate chains were shortened by the Al 2 O 3 and/or Y 2 O 3 introduced into 1W glass. This structural change increased the fraction of protons bound to oxygen atoms in the terminal PO 4 (i.e., the Q 1 unit) of the phosphate chains. Because the protons bound to terminal Q 1 units in phosphate chains tightly bind to oxygen atoms, as opposed to the protons bound to inner Q 2 units in phosphate chains, we attributed the reduced mobility of proton carriers upon introducing AlO 3/2 and/or YO 3/2 into 1W glass to the shortening of phosphate chains. From these results we propose that to obtain a highly proton-conducting glass after APS, the glass must have a composition of O/P 2 units.

Recently, we developed a label-free detection method based on optical diffraction, and implemented it in on our fabricated micro- and nanofluidic device. This detection method is simple and useful for detecting biomolecules, but the device fabrication consists of complicated processes. In this paper, we propose a simple method for fabricating the micro- and nanofluidic device; the fabrication combines laser interference lithography with conventional photolithography. The performance of a device fabricated by the proposed method is comparable to the performance of the device in our previous study.

We propose the fabrication of surface relief holograms via selective SiO2 deposition on soda-lime silicate glass substrates. Initially, the original hologram was recorded on an azobenzene photosensitive polymer film coated on the soda-lime silicate glass by irradiation with a conventional continuous wave Ar+ laser with a wavelength of 514.5 nm. The hologram was transferred to the soda-lime silicate glass surface via a corona discharge treatment as an index modulation hologram, which was created by partial substitution of protons for sodium ions during the corona discharge treatment in air. After the corona discharge treatment, the polymer film was removed from the substrate. The diffraction efficiency of the index hologram on the soda-lime silicate glass was estimated to be 5.8 × 10-2% at a wavelength of 532 nm. Finally, the glass substrate was subjected to corona discharge treatment in air with vaporized cyclic siloxane. A surface relief hologram with the diffraction efficiency of 2.3% was successfully fabricated on the soda-lime silicate glass.

One of the most important achievements in the field of spintronics is the development of magnetic tunnel junctions (MTJs). MTJs exhibit a large tunneling magnetoresistance (TMR). However, TMR is strongly dependent on biasing voltage, generally, decreasing with applying bias. The rapid decay of TMR was a major deficiency of MTJs. Here we report a new phenomenon at room temperature, in which the tunneling magnetocapacitance (TMC) increases with biasing voltage in an MTJ system based on Co40Fe40B20/MgO/Co40Fe40B20. We have observed a maximum TMC value of 102% under appropriate biasing, which is the largest voltage-induced TMC effect ever reported for MTJs. We have found excellent agreement between theory and experiment for the bipolar biasing regions using Debye-Fröhlich model combined with quartic barrier approximation and spin-dependent drift-diffusion model. Based on our calculation, we predict that the voltage-induced TMC ratio could reach 1100% in MTJs with a corresponding TMR value of 604%. Our work has provided a new understanding on the voltage-induced AC spin-dependent transport in MTJs. The results reported here may open a novel pathway for spintronics applications, e.g., non-volatile memories and spin logic circuits.

We investigated electrochemical substitution involving the electrochemical oxidation of hydrogen with proton injection into an oxide glass. This was accompanied by the electrochemical reduction of sodium ions and the discharge of metallic sodium out of the glass. This is referred to as the alkali–proton substitution technique and we applied it to a sodium-containing phosphate glass. The thermal stability of the 1WO 3 –35NaO 1/2 –8NbO 5/2 –5LaO 3/2 –51PO 5/2 glass that previously deformed at > 250 °C improved to 350 °C after alkali–proton substitution technique by the introduction of AlO 3/2 and/or YO 3/2 . However, the mobility of the proton carriers decreased by 1/20–1/50 by the introduction of AlO 3/2 and/or YO 3/2 while the thermal stability improved. Based on infrared absorption spectra the reduced mobility can be attributed to the increase in protons that are tightly bound to oxygen by weak hydrogen bondings.

Corona discharge reflects the spatial migration of alkali ions over a gap between two glass plates. This study examined stacked glass plates containing different alkali ions treated with the corona discharge plasma generated by applied voltage of 4.5 kV at 200 °C. Protons generated at the anode electrode penetrate into the potassium-ion-containing upper glass plate, which is located 5 mm below the anode electrode. Potassium ions intruded into the lower glass plate containing sodium ions placed on the cathode electrode, even over a 1 mm gap separating the plates. Finally, the sodium ion discharged on the cathode electrode. The hydrogen atmosphere was effective at inhibiting the potassium ion reaction with ambient gases during the spatial migration between the two glass plates.

This paper presents the effect of mold stiffness on the surface flatness of mold-pressed glass for glass molding and imprint processes. Phosphate and borosilicate glasses were pressed at their viscoelastic temperature region using flat molds of several kinds and subsequently cooled to room temperature. Surface flatness of the mold-pressed glasses was examined using a stylus surface profilometer. The glass surface curvature was observed after spontaneous demolding by thermal shrinkage stress of the glass and the mold during cooling. The curvature decreased with increasing mold stiffness, as determined by the Young's modulus and mold thickness. The curvature also decreased with decreasing cooling rate during cooling, which was discussed in terms of the glass fragility. It was demonstrated that the Young's modulus, mold thickness, and cooling rate are key factors for the control of the molded glass surface flatness.