On the Effect of Ultrasound to Nematic Liquid Crystal

Abstract

Corrosion-related defects in pure Al and AA 2037 Al alloy have been investigated by positron beam-based Doppler broadening energy spectroscopy. Defect profiles have been analyzed by measuring the S parameter as a function of incident positron energy up to 30 keV. When pure Al samples are immersed in 1M NaOH for various times, a significant increase in the S parameter near the surface is observed. This implies that the corrosion process involves the creation of defects and nanometer voids. In contrast, a significant decrease in the S parameter is observed after the corrosion of water-quenched Al alloy by the same method, which is interpreted as being a result of Cu enrichment near the metal-oxide interface layer.

Influence of buffer layers on the microstructure of MOVPE grown a-plane InN

“…But along with that broadening, the center of the peak is also shifted with respect to the ð2 2 0 4ÞÀpeak of sapphire. This represents an overall tilting of the epitaxial layer with respect to sapphire substrate, and is similar to the Nagai-like tilt observed in other material systems [13]. Since such a shift does not appear for Q x J½1 1 0 0 conditions, this allows us to conclude that the tilting of the ð1 1 2 0ÞÀplanes occur along the c-direction as shown schematically in Fig.…”

Optimization of a-plane InN grown via MOVPE on a-plane GaN buffer layers on r-plane sapphire

“…This arises because of the in-plane anisotropy in the lattice-mismatch and the miscut of the substrate. Such a shift is basically a signature of ''Nagai-tilt'' [13] in the layer, details of which are discussed in a separate work [14]. In the RSM, along with the InN-peak there is an additional peak which appears for all the InN samples grown on GaN buffer layers.…”

X-ray Triple-Crystal Diffractometry and Transmission Electron Microscopy Characterization of Defects in Lattice-Mismatched Epitaxic Structures

“…In our case, TEM diffraction analysis showed the MDs to be of the 60 type. It was shown by Nagai (1974) that, when the substrate surface was inclined with respect to (001) plane, such a network made the layer planes slope from the substrate ones. We found that the tilt rose upwards.…”