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The surface tension of Bi2O3–B2O3–SiO2 melts was measured using the ring method over the temperature range 973–1573 K. The composition and temperature dependences of the surface tension were investigated. The surface tension of Bi2O3–B2O3–SiO2 melts showed a maximum near 60–70 mol% Bi2O3 and decreased with increasing B2O3/SiO2 ratio at 1373 K. By assuming a linear relationship between the surface tension and the Bi2O3 content of binary silicate melts, the surface tension factor of Bi2O3 was determined to be 211 mN m−1 at 1373 K. The surface tension values calculated using the surface tension factor of each single component showed the largest deviation from the measured values when the Bi2O3 content was around 50–60% and were dependent on the B2O3 content. The temperature coefficient of surface tension had positive values at low Bi2O3 contents (less than 30–40 mol%) and negative values at high Bi2O3 contents.

We propose a novel noncontact method for measuring the viscosity of high-temperature glass melt using a small amount of sample. This method combines the electric-field tweezers system developed for measuring the local and dynamic surface properties of soft condensed materials and the hot-thermocouple technique for in situ observation and measurement of high-temperature liquids. The viscosity of B2O3 melt was measured in the temperature range of 873 to 1473 K. The temperature dependence of the viscosity presented in this work is in reasonable agreement with that reported in the references.

The effect of mixing ratio, firing temperature and matrix glass composition on afterglow luminance property of SrAl 2 O 4 : Eu 2+ ,Dy 3+ -glass composites were investigated. As a result, the brightness showed a maximum at 35 mass % of the mixing ratio of the phosphor for the glass and 780°C of the firing temperature. And it was increased with decreasing the Na 2 O content of the matrix glass. From the backscattered electron and the EDX analysis, it is thought that the intermediate layers generated between the phosphors and the Na 2 O-poor matrix glass work as antireflective and the phosphor particles in the composite emit phosphorescent light more efficiently. As higher the basicity parameter, B, the intermediate layer was clearer, which means that the reactivity at the phosphor/glass boundaries was lower, and the narrow reaction layers was formed.

BaO–TeO2 thin films were prepared from tellurium(VI) alkoxide by a sol–gel method and their structure was investigated by X-ray diffractometry, Fourier transform infrared spectrometry, and 125Te static nuclear magnetic resonance. Their crystallization temperature (Tc), optical transmittance, and dielectric constant were measured, and their refractive index was calculated from the transmission spectra. The results indicate that the BaO–TeO2 thin films were composed of TeO6 and TeO4 units, and had a Tc of ∼520°C, refractive index of ∼1.79, dielectric constant of ∼20. These films had a Tc higher than the glass prepared by a melt-quench method, but their refractive index and dielectric constant were lower. These differences may be due to differences in their structural units.

Scatterers observed in lithium tetraborate (Li2B4O7) crystals grown by the Czochralski (CZ) method, were examined. It was revealed that the scattering source may decrease transparency in the ultraviolet (UV) region, which is an important property for application in nonlinear devices in the UV region. Parameters necessary for the reproducible growth of scatterer-free Li2B4O7 crystals were also investigated and scatterer-free Li2B4O7 crystals were successfully grown in dry air flow. Particles forming the scattering source were evaluated and the H concentration of the crystals was also examined.

Dielectric constants were measured for phosphate and silica glass systems in the frequency region of 1 to 10 GHz using the resonance cavity method. Compositional dependence of dielectric constant and tangent loss were discussed. The effect of the cations on the ε indicates that ε increases in the order, R:Mg

The surface tensions of xPbO-(100−x) B2O3 (x = 30–80 mol%) and xBi2O3-(100−x) B2O3 (x = 0–100 mol%) melts were measured using the ring method over the temperature range 973 to 1373 K. The compositional and temperature dependences of surface tension were investigated. Addition of PbO and Bi2O3 to B2O3 increased the surface tensions of their respective PbO-B2O3 and Bi2O3-B2O3 melts. The surface tension showed a maximum at 60 mol% PbO in the PbO-B2O3 melts and at 70–80 mol% Bi2O3 in the Bi2O3-B2O3 melts. The temperature coefficient of surface tension was examined on the basis of its relationship to the structure, and it was suggested that the temperature coefficient of surface tension decreases with an increasing content of four-coordinated boron.

We report the vacuum ultraviolet (VUV) spectroscopy of APLF + Nd and APLF + Er glass, with composition 20Al(PO3)3-80LiF + 1NdF3 and + 1ErF3 (in mol%). APLF + Nd and APLF + Er have a dominant fluorescence peak at 185 nm and 168 nm with decay times of 4.5 ns and 5.8 ns, respectively. Fluorescence from APLF + Nd is attributed to 4f25d → 4f3 transitions in neodymium (Nd) while fluorescence from APLF + Er is due to spin allowed transition in erbium (Er). This is the first report of VUV fluorescence from rare earth ions doped in glass hosts, which could provide the basis for mass production of VUV emitting materials. Our results also suggest the potential of using APLF + Nd and APLF + Er as neutron scintillators during inertial confinement fusion.

The densities of xBi2O3·(100−x)B2O3 binary melts (x= 0–100 mol%) have been measured systematically in the temperature range of 973 to 1373 K using the Archimedean double-bob method. In addition, the molar volume and coefficient of volume expansion have been determined from these density measurements. The density of melts in the Bi2O3–B2O3 binary system decreased with increasing temperature for all compositions, and increased with increasing Bi2O3 content. The molar volume calculated at 1273 K showed a minimum at around 20–30 mol% Bi2O3. The deviation of molar volume from ideality and the partial molar volumes of B2O3 and Bi2O3 single-component melts were calculated, and the relationships between these properties and Bi2O3 content were investigated. The Δ(MV) (deviation of molar volume from ideality) was negative in the Bi2O3–B2O3 binary melts and showed a minimum of −7.5 cm3 (−17.3%) at 40 mol% Bi2O3 and 1273 K. The PMV (partial molar volume) of the B2O3 melt decreased with increasing Bi2O3 content, up to 70 mol% Bi2O3, and was constant above 70 mol% Bi2O3. The PMV of the Bi2O3 melt was constant up to 30 mol% B2O3 (considered from the viewpoint of Bi2O3), and then decreased sharply with further addition of B2O3. The coefficient of volume expansion increased sharply up to 20 mol% Bi2O3 and decreased with further addition of Bi2O3 at 1273 K. From this result, it can be inferred that the temperature-induced structural changes taking place in the melts are greatest at 20 mol% Bi2O3.

The density, surface tension, and viscosity of the melts from the PbO-B2O3-SiO2 system have been measured at temperatures in the range 1073–1473 K. The effect of composition on these properties was also investigated. The density of the melt was found to increase linearly with increasing PbO content. Molar volume was derived from the density data, and its deviation from the additivity of partial molar volumes was calculated. These deviations in molar volume from those obtained from additivity rules have been used along with the ratio of various coordination numbers of boron (as reported by Bray) to discuss the structure of the melts. The surface tension was found to decrease with decreasing SiO2/B2O3 ratio, and to increase in the range of the PbO content between 30 and 60 mol%, showing a maximum at ∼60 mol% PbO, and then decreased with further additions. This result suggested that the surface tension would be affected primarily by the B2O3 content in the range of the PbO content between 30–60 mol%, and mainly by the PbO content in the range of the PbO content >60 mol%, respectively. The viscosity of the melt was found to decrease linearly with increasing PbO content. The results obtained indicate that the increase in viscosity with B2O3 was half that of SiO2 (on a molar basis), and an empirical equation has been proposed for the viscosity as a function of mole fraction.

The density, surface tension and viscosity of the 50RO–50P2O5 (R: Mg, Ca, Sr, Ba and Zn) glass melts have been measured over the range, 1073–1623 K. The effects of R cations on these properties have been investigated. The density of the melt was found to increase in the order, R: Mg Ca Zn Sr Ba, with increasing molar weight of cation. The surface tension in the temperature range of 1373–1473 K increased approximately with cation in the order, R: Zn Ba Mg Ca Sr. The viscosity and the negative, temperature coefficient of surface tension increased in the order, R: Ba Sr Ca Zn Mg. All melts exhibited negative temperature coefficients of surface tension. The effect of Mg and Zn cations on the properties were different to that for Ba, Sr, and Ca cations and this is discussed using bulk glass data published in a previous report. The features of Mg and Zn metaphosphate glass melts, that is high values of viscosity, and temperature coefficient of surface tension, are related to the small Oxygen Coordination Number of the cations (=4) when compared with those of Ca, Sr, Ba metaphosphate glass melts.

Refractive indexes of oxide glasses: silica, borate, silicate, aluminate, germanate, tellurite, antimonate and heavy metal gallate are measured in the wavelength range of 0.40–5.03 μm. The zero material dispersion wavelength (ZMDW) was determined using the refractive index data. To predict the ZMDW, we calculated the molecular electronic polarizability, α i , of oxide glasses using the Lorentz-Lorenz equation. An empirical equation between ZMDW and α i was obtained, from which the ZMDW from the compositional parameter, α i can be calculated.

Refractive index dispersion curves in the wavelength region of 0.40 to 5.03 μm are presented for multi-component oxide glass systems: borate, silicate, aluminate, germanate, tellurite, antimonate and heavy metal gallate. The material dispersion was determined using the refractive index data. Reflection spectra in the ultraviolet and infrared regions were measured to investigate the effects of electronic transitions and lattice vibrations on the material dispersion. Thallium tellurite, thallium antimonate and lead gallate glasses exhibit zero material dispersion wavelengths (ZMDWs) over 2.4 μm. The factors affecting the ZMDW are discussed.

Accurate refractive indexes of oxide glasses—silica, silicate, borate, aluminate, tellurite, antimonate, and heavy metal gallate glasses—are presented in the wavelength range 0.265 to 1.710 μm. Factors affecting the refractive index dispersion are discussed by using the single-oscillator Drude-Voigt equation. The values of nd at 0.5876 μm are affected mainly by the average resonance wavelength at the ultraviolet region through all of the glass systems. The distinguishing features of borate glasses—relatively high refractive index and low dispersion—are related to the large number of molecules, N, in a unit volume, compared with those of the other glasses. The number N determined by density measurements is related to the fraction of the four-coordinated borons estimated by Greenblatt and Bray.

The effects of composition on refractive index, density, glass transition temperature, and ultaviolet-visible and infrared transmissions were studied for gallate glasses containing a large amount (80mol%) of PbO, Bi2O3 and Tl2O. The resonance wavelengths of Pb2+, Bi3+ and Tl+ were determined from the reflection spectra of gallate glasses. The refractive indexes of gallate glasses were measured down to the fourth decimal in the wavelength range of 480nm to 1710nm using the minimum deviation method. Refractive index in the system Bi2O3-PbO-Ga2O3 increases as PbO is substituted for Bi2O3. Refractive index in the systems Tl2O-PbO-Ga2O3 and Tl2O-Bi2O3-Ga2O3 increases as Tl2O content increases. Factors affecting the refractive index of heavy metal gallate glasses are discussed by using the single-oscillator Drude-Voigt equation.

Refractive indexes of barium borate-based glasses were measured in the wavelength range from 0.265 to 1.710μm by using the minimum deviation method. Factors affecting the refractive index dispersion are discussed by using the single-oscillator Drude-Voigt equation. Borate glasses are characterized by the larger number N of molecules in a unit volume than that for silicate glasses. The feature of borate glasses, that is, relative high refractive index and low dispersion, is dominated by the number N which is related to the fraction of four-coordinated borons estimated by Green-blatt and Bray. Borate glasses containing high valency cations, e.g., Y3+, La3+, Ti4+, Nb5+, Ta5+, posess higher refractive indexes and higher dispersion than barium borate binary glasses.

Experimental results are presented on the neutron scintillating properties of a custom-designed Praseodymium-doped Lithium-6 glass for a new deuterium-deuterium (DD) fusion scattered-neutron detector. Luminescence was observed at 278 nm-wavelength, and time-resolved measurement yielded ~5.4 ns decay time for neutron excitation. Actual time-of-flight data in laser fusion experiments at the GEKKO XII facility at the Institute of Laser Engineering (ILE), Osaka University reveal that it can clearly discriminate fusion primary-neutrons from the x-ray signals. This material promises the realization of more accurate DD fusion scattered-neutron diagnostics. Design work for a scattered-neutron detector is being conducted for the Fast Ignition Realization Experiment (FIRE-X) at ILE.