Structural state of III nitride layers implanted with erbium ions

The defect structure of AlGaN/GaN superlattices and GaN layers grown through vapor-phase epitaxy from organometallic compounds is investigated using x-ray diffraction analysis before and after implantation with erbium ions at an energy of 1 MeV and a dose of 3 × 10¹⁵ cm^?2, as well as after annealing. For a superlattice with a total thickness larger than the implantation depth, the satellites of the superlattice region strained under the action of ions disappear in the x-ray diffraction pattern after annealing at temperatures higher than 900°C. This suggests that the radiation-induced defects responsible for the positive deformation in the layer are annealed at these temperatures. However, annealing even at a temperature of 1050°C does not lead to complete recovery of the initial state and the positive deformation in the remaining regions is caused by residual defects. An analysis of the x-ray diffraction patterns demonstrates that, in samples with thin superlattices located at the depth corresponding to maximum radiation damage, the periodic structure that disappears after implantation at a dose of 3 × 10¹⁵ cm^?2 is not recovered even after annealing at a temperature of 1050°C. This inference is confirmed by the results of examinations with an electron microscope.     

Dislocation-related luminescence in Er-implanted silicon

The behavior of luminescence spectra and structural defects in single crystal Czochralski silicon after erbium implantation at 1–1.8 MeV energies and 1×10¹³ cm⁻² dose with subsequent annealing at 1000–1200°C for 0.25–3 h in argon and a chlorine-containing ambience (CCA) was studied by photoluminescence (PL), transmission electron microscopy and chemical etching/Nomarski microscopy. We have found that annealing in CCA gives rise to dislocation loops and pure edge dislocations with dominant dislocation-related lines in the PL spectrum. Pure edge dislocations are responsible for the appearance of the lines.     

Electron-conformational interactions and functioning of enzyme molecules

Electron-configuration interaction is one of the most general physicochemical approaches used to explain an enzymes functioning. Studying enzymatic reactions requires investigation of the motions of nuclei on a certain PES . In order to obtain the shape of the PES numerous calculations of the total energy of the enzyme–substrate complex were calculated, and are presented in this paper.     

Rheological and Electrical Properties of the Suspensions of Differently Oxidized Carbon Blacks in Polar and Apolar Dielectric Dispersion Media

The results of the investigation of the rheological characteristics and electrical resistance of the suspensions of carbon black with various degrees of oxidation in apolar vaseline oil and polar castor oil are reported. It is established that, regardless of the degree of oxidation, the strength of the structure-forming bonds between aggregates of carbon black in vaseline oil is higher than that in castor oil.     

高性能聚芳醚酮的合成与性能(Ⅰ)——对苯二酚、联苯二酚、4,4′,-二氟二苯酮三元共聚体系

聚醚醚酮(PEEK)具有突出的耐高温水解和耐辐照性能以及良好的断裂韧性,现已在核能、宇航等高技术领域得到应用。研制新型聚芳醚酮是目前十分活跃的课题。本文采用亲核取代路线,以对苯二酚、联苯二酚、4,4′-二氟二苯酮为单体合成了一系列含亚联苯结构的新型聚芳醚酮,并对基基本性能进行了测定。     

Spectral clearance of a focusing operator

Functional Analysis and Its Applications -