Transparent glass ceramic materials, with microstructures comprised of dispersed nanocrystallites in a residual glass matrix, offer the prospect of nonlinear optical properties. However, good transparency requires low optical scattering and low atomic absorption. The attenuation of light due to scattering (turbidity) will depend upon the difference in refractive index of the two phases and the size and distribution of crystals in the glass. Here, we model the glass ceramic as a late-stage phase-separated structure, and compute scattering in this model. We find that the turbidity follows a k8R7 relationship, where k is the wave vector of light in the glass ceramic and R is the average radius of the crystals in the glass.

Tungsten trioxide adopts a variety of structures which can be intercalated with charged species to alter the electronic properties, thus forming “tungsten bronzes.” Similar effects are observed upon removing oxygen from $\mathrm{W}{\mathrm{O}}_3$. We present a computational study of cubic and hexagonal alkali bronzes and examine the effects on cell size and band structure as the size of the intercalated ion is increased. With the exception of hydrogen (which is predicted to be unstable as an intercalate), the behavior of the bronzes are relatively consistent. $\mathrm{Na}\mathrm{W}{\mathrm{O}}_3$ is the most stable of the cubic systems, although in the hexagonal system the larger ions are more stable. The band structures are identical, with the intercalated atom donating its single electron to the tungsten $5d$ valence band. A study of fractional doping in the ${\mathrm{Na}}_x\mathrm{W}{\mathrm{O}}_3$ system $(0⩽x⩽1)$ showed a linear variation in cell parameter and a systematic shift in the Fermi level into the conduction band. In the oxygen-deficient $\mathrm{W}{\mathrm{O}}_{3-x}$ system the Fermi level undergoes a sudden jump into the conduction band at around $x=0.2$. Lastly, three compounds of a layered $\mathrm{W}{\mathrm{O}}_4\bullet \alpha ,\omega$-diaminoalkane hybrid series were studied and found to be insulating, with features in the band structure similar to those of the parent $\mathrm{W}{\mathrm{O}}_3$ compound that relate well to experimental UV-visible spectroscopy results.

In situ synchrotron x-ray diffraction experiments on bare palladium nanoclusters prepared by inert-gas aggregation and size selected (1.7–6.0 nm) show significant changes in lattice parameter upon hydrogen loading and a narrowing of the miscibility gap, as the cluster size decreases. The results show that the miscibility gap is open for all cluster sizes studied, in contrast to previous literature results from surfactant-encapsulated palladium clusters. We interpret these results by showing that the nature of the surface is critical in the hydrogenation behavior of the nanoclusters.

We study the coalescence of nanoscale metal clusters in an inert-gas atmosphere using constant-energy molecular dynamics. The coalescence proceeds via atomic diffusion with the release of surface energy raising the temperature. If the temperature exceeds the melting point of the coalesced cluster, a molten droplet forms. If the temperature falls between the melting point of the larger cluster and those of the smaller clusters, a metastable molten droplet forms and freezes.