Materials Literature
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The discovery of single–bubble sonoluminescence has led to a renewed interest in the forced radial oscillations of gas bubbles. Many of the more recent studies devoted to this topic have used several simplifications in the modelling, and in particular in accounting for liquid compressibility and thermal processes in t…
Minor addition of Cu to Nd4.5Fe77B18.5 melt-spun alloy is effective on reducing the grain size of the Fe3B/Nd2Fe14B nanocomposite permanent magnet produced via the crystallization route from the amorphous phase, thereby improving hard magnetic properties. Three-dimensional atom probe and transmission electron microsco…
Recent observations of the collapse of single bubbles or clouds of cavities trapped within stationary acoustic fields have shown the production of light and these phenomena have been dubbed single– or multiple–bubble sonoluminescence. The experimental observation of the variations in the bubble radius with time, with…
Optical absorption and luminescence experiments were used to study the photoconversion of neutral oxygen vacancies (F centers) in MgO single crystals thermochemically reduced at elevated temperatures. In crystals with an undetectable concentration of hydride ions and a moderate concentration of F centers $(\ensuremath…
The electronic properties of carbon nanotubes are investigated in the presence of a magnetic field perpendicular to the nanotube axis and disorder introduced through site-energy randomness. The magnetic field is shown to induce a metal-insulator transition for the metallic $(9,0),(12,0)\dots{}$ nanotubes in the absenc…
We have used quantitative X-ray microscopy in combination with Scanning Force Microscopy to monitor the phase separation of spun cast thin films of polystyrene and poly(methyl methacrylate) blends upon annealing. Both techniques complement and enhance each other in elucidating the complicated structures that develop a…
The $(1\ifmmode\times\else\texttimes\fi{}1)$ to $(2\ifmmode\times\else\texttimes\fi{}1)$ surface phase transition of the hydrogen-covered diamond (111) surface is investigated by core level spectroscopy, low-energy electron diffraction, and measurements of the electron affinity. The latter method is shown to be a reli…
Over the last few years, a large number of chemists and engineers working in synthesis and processing have developed an interest in sonochemistry: the applications of power ultrasound in chemistry. Scientific papers reporting the remarkable results obtained using sonochemistry are plentiful and yet the subject still d…
Combining spectroscopic methods probing both occupied as well as unoccupied electronic states, the surface electronic structure of ex situ prepared boron-nitride films is analyzed and compared to experimental and theoretical bulk-electronic properties taken from the literature. X-ray photoelectron spectroscopy is appl…
The degree of crystallinity of a set of monoclinic (alpha) isotactic poly(propylenes), prepared by a metallocene-type catalyst, were determined at room temperature. Three different methods were used: density, enthalpy of fusion, and wide-angle X-ray scattering, and the results compared. The relation between the heat o…
The catalytic oxidation of CO on O-precovered Pt(111) surfaces has been modeled via ab initio local-density-functional calculations. It is shown that at coverages of ${\ensuremath{\Theta}}_{\mathrm{O}}\ensuremath{\sim}0.5$ the coadsorption of CO stabilizes the chemisorbed molecular precursor of ${\mathrm{O}}_{2}$ over…
Dielectric ac measurements in the frequency range of ∼1 mHz–1 MHz were performed on β-Ta2O5 samples made by chemical vapor deposition. A method of estimating the dielectric constant and the dc conductivity from the dielectric response was developed. The high-frequency dielectric constant was found to be 25.84 with no…
The perovskite ${\mathrm{SeCuO}}_{3}$ is unusual for possessing (i) a very small $A$-site $({\mathrm{Se}}^{4+})$ radius, (ii) highly distorted Cu-O-Cu bond angles $\left(\ensuremath{\alpha}\right)$, and (iii) a ferromagnetic (FM) ground state. Negative chemical pressure is applied by replacing Se with Te in solid solu…
Multiwall carbon nanotubes were irradiated by 2.5-MeV electrons with different fluences. Nanotubes appear to be very resistant to radiation, without radiolysis effects. The radiation-induced defects, which were nearly exclusively point defects, were found to significantly modify the electronic properties of the tubes…
Sonoluminescence is investigated experimentally from the perspective of the dynamics of a single inertial cavitation bubble levitated in an acoustic sound field. The discussion includes bubble levitation, the inertial cavitation threshold, the parameter space in which stable singlendash;bubble sonoluminescence is obse…
We examined the effects of the tie-molecule fraction on the yielding behavior of two isotactic polypropylenes, one having little ethylene content and the other as the homopolymer with no ethylene. The tie-molecule fraction of the samples used in this study was controlled by blending ethylene-α-olefin of an α-olefin co…
The full equations are derived for the resistances to the transport of heat and electricity through boundaries of thermoelectrics. We show that the boundary resistances of heat and electricity are proportional. This relationship is a boundary form of the Wiedemann–Franz law. We also show there is a boundary Seebeck co…
Thermal treatment is reported to convert finely dispersed diamond powder to multiwall carbon nanocapsules containing fullerenes such as ${\mathrm{C}}_{60}$. We investigate the internal dynamics of a related model system, consisting of a $\mathrm{K}@{\mathrm{C}}_{60}^{+}$ endohedral complex enclosed in a ${\mathrm{C}}_…
In acoustic cavitation the spatial variation and time–dependent nature of the acoustic pressure field, whether it is a standing or propagating wave, together with the presence of other bubbles, particles and boundaries produces gradients and asymmetries in the flow field. This will inevitably lead to non–spherical bub…
We present a computationally efficient first-principles scheme to calculate ${\ensuremath{\epsilon}}_{2}(\ensuremath{\omega})$ for crystalline insulators, including the electron-hole interaction. The effective Hamiltonian for electron-hole pairs contains both the exchange and direct parts of this interaction. An itera…