Ordered semiconductor In2O3 nanowire arrays are uniformly assembled into hexagonally ordered nanochannels of anodic alumina membranes (AAMs) by electrodeposition and oxidizing methods. Their microstructures were characterized by x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. A blue-green photoluminescence (PL) band in the wavelength range of 300–650 nm was observed in the In2O3/AAM assembly system. The PL intensity and peak position depend on the annealing temperature, which is mainly attributed to the singly ionized oxygen vacancy in the In2O3 nanowire array system.

Large-scale single-crystalline CdO nanowires have been successfully fabricated from the electrochemical deposition mixture film of Cd and Te at 450°C, and characterized by x-ray diffraction (XRD) powder, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM and TEM images show that these nanowires are uniform with diameters of about 40–60 nm, length up to several tens micrometres. XRD and selected area electron diffraction analyses altogether indicate that these CdO nanowires crystallize in a NaCl cubic structure. The growth mechanism of these nanowires is also proposed as vapour–liquid–solid mechanism, in which Te serves as a liquid-forming agent.

The sound absorption behaviour of an open celled aluminium foam fabricated by investment casting method was examined and correlated with the pore size, sample thickness and backing air gap depth in the present study. The foam shows low sound absorption coefficients at relatively low frequencies or with relatively thin sample thickness due to its 90% or higher open porosity. As frequency or sample thickness increases, the sound absorption is significantly enhanced. Furthermore, if the sample is backed with an air gap, the approximate periodical resonant absorption peaks emerge from the background and shift towards low frequencies with increasing the gap depth. It is also found that the present aluminium foam has even better absorption performance than polyurethane foam, with almost the same pore parameters as the former. The observation on the pore surface and further experiments demonstrate that the difference is attributed to rougher pore surface of the aluminium foam that makes the sound wave loss increase through enhanced friction between the air and the surface.

1The optic vibrational (confined and interface) modes and the electron-phonon and hole-phonon interactions are obtained, in dielectric continuum model, for two diluted magnetic semiconductor structures: a single well of Cd1−xM nxT e/Cd1−yM gyT e with the magnetic ions in the well, and a double well of CdT e/Cd1−xM nxT e, in which a thin layer of the magnetic material is grown in the middle of the structure. The scattering rates for the intra-and the inter-subband transitions are obtained for electrons and holes.

We present a detailed study of dissipation by electrons in the non-linear transport regime of harmonically confined quantum wires in GaAs/AlAs structures through emission and absorption of confined and interface optical phonons. An applied magnetic field perpendicular to the interfaces is used to modulate the natural harmonic frequencies in order to explore situations in and off resonance with the vibrational modes. Our results show that electrons absorb both confined phonons and interface phonons over wide angles and backwards, at low drift velocities. The emission occurs both forwards and backwards and dominates entirely for high drift velocities. The confined phonons play the dominant role in the dissipation, even for quantum wires inside thin quantum wells and with a magnetic field strength selected to make the harmonic levels in resonance with the AlAs-like interface mode.