Publications by authors named "V G Dorogan"

We performed a retrospective analysis of the encephalometric parameters of the brain hemispheres in children aged 8 years (30 boys and 30 girls) and 11 years (30 boys and 30 girls). The variability of the parameters of the brain hemispheres depending on age and sex was studied. In 8-year-old children, sex differences were revealed in a significant number of basic parameters: the length of the right and left hemispheres and the lengths of the left frontal lobe, right parietal lobe, right and left occipital lobes.

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In this study we report in-plane nanotracks produced by molecular-beam-epitaxy (MBE) exhibiting lateral self-assembly and unusual periodic and out-of-phase height variations across their growth axes. The nanotracks are synthesized using bismuth segregation on the GaAsBi epitaxial surface, which results in metallic liquid droplets capable of catalyzing GaAsBi nanotrack growth via the vapor-liquid-solid (VLS) mechanism. A detailed examination of the nanotrack morphologies is carried out employing a combination of scanning electron and atomic force microscopy and, based on the findings, a geometric model of nanotrack growth during MBE is developed.

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We report on AlxGa1-xN heterostructures resulting from the coherent growth of a positive then a negative gradient of the Al concentration on a [0001]-oriented GaN substrate. These polarization-doped p-n junction structures were characterized at the nanoscale by a combination of averaging as well as depth-resolved experimental techniques including: cross-sectional transmission electron microscopy, high-resolution X-ray diffraction, Rutherford backscattering spectrometry, and scanning probe microscopy. We observed that a small miscut in the substrate orientation along with the accumulated strain during growth led to a change in the mosaic structure of the AlxGa1-xN film, resulting in the formation of macrosteps on the surface.

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We report room-temperature Raman scattering studies of nominally undoped (100) GaAs1−xBix epitaxial layers exhibiting Bi-induced (p-type) longitudinal-optical-plasmon-coupled (LOPC) modes for 0.018 ≤ x ≤ 0.048.

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We compare InAlAs/GaAs and InGaAs/GaAs strained-layer superlattices (SLSs) as dislocation filter layers for 1.3-μm InAs/GaAs quantum-dot laser structures directly grown on Si substrates. InAlAs/GaAs SLSs are found to be more effective than InGaAs/GaAs SLSs in blocking the propagation of threading dislocations generated at the interface between the GaAs buffer layer and the Si substrate.

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