The dependence of the glass transition temperature on silicate composition as well as on borate composition is discussed. Some new experimental results on borosilicate glass-enamels are put together with the existing literature data. It is demonstrated that in the glass transition interval the activation energy E(Tg) for viscous flow is related to the glass transition temperature. The activatio...

• In a study of the optical properties of coactivated xuminescent glasses, CO c c r^ 2+ ^TJ3 + (1) J r ^,3+ XT,3+(2) , ^mr u ansfer of -nergy trom UO_ to Nd and troiTi Ce to Nd has been /-S 2 PMÜ observed and it has been shown that for both of these ion pairs this energ;' ^Jj^ lntcr(.■h>ln^^ is partly achieved by radiationless transfer mechanisms. In ^^ 3+ 3 + this paper the transfer of energy ...

We use classical molecular dynamics simulations to study the dynamics of sodium atoms in amorphous Na2O-4SiO2. We find that the sodium trajectories form a well connected network of pockets and channels. Inside these channels the motion of the atoms is not cooperative but rather given by independent thermally activated hops of individual atoms between the pockets. By determining the probability ...

Transparent ceramics are important for scientific and industrial applications because of the superior optical and mechanical properties. It has been suggested that optical transparency and mechanical strength are substantially enhanced if transparent ceramics with nano-crystals are available. However, synthesis of the highly transparent nano-crystalline ceramics has been difficult using convent...

Silicate glass has been used as an analog for silicate melts to understand the nature of dense magmas in Earth’s mantle. To effect Al2O3 on sound velocity and structure MgSiO3 glass, this study, combined with Brillouin scattering diamond anvil cells (DACs), acoustic MgSiO3?5 mol%Al2O3 (MA1) MgSiO3?24.5 (MA2) were measured up 20 42 GPa, respectively. Our studies show that incorporation could inc...

The manufacture of sintered glasses and glass-ceramics, glass matrix composites, and glass-bounded ceramics or pastes is often affected by gas bubble formation. Against this background, we studied sintering and foaming of barium silicate glass powders used as SOFC sealants using different powder milling procedures. Sintering was measured by means of heating microscopy backed up by XPD, differen...

The present review is intended to revisit the advances and debates in the comprehension of the mechanisms of subcritical crack propagation in silicate glasses almost a century after its initial developments. Glass has inspired the initial insights of Griffith into the origin of brittleness and the ensuing development of modern fracture mechanics. Yet, through the decades the real nature of the ...

The particle size distribution of aqueous metal-oxide slurries can evolve during the polishing of optical glass in response to changes in mechanical and chemical process factors. The size-evolution phenomenon and its consequences were systematically studied in a planar continuous-polishing process. The concurrent application of electrokinetic techniques to characterize common optical shop mater...