Papers by Keyword: Monocrystal

Abstract: 3C-SiC layers of different microstructures (monocrystalline (100) and (111) oriented and polycrystalline) were implanted with high energy (800 keV) ¹²⁹Xe⁺⁺ ions. Implantations were performed at room temperature (RT) and at 500 °C using two different fluences of Φ₁ = 1x10¹⁶ and Φ₂ = 1x10¹⁷ at/cm². Surface blistering was only observed for RT and Φ₂ implantations into poly-SiC material while mono-SiC kept rather smooth surface. This was due to more homogeneous Xe bubbles distribution (200 nm deep) in the mono-SiC than in the poly-SiC. Xe retention was found to be almost complete for all samples. Some Xe enhanced diffusion was detected in the poly-SiC material which was attributed to grain boundaries. Some irradiation-induced oxidation effect was evidenced, O element being located at the depth where Xe bubbles are accumulating. This was more pronounced for poly than for mono-SiC. These results demonstrate that SiC microstructure affects many aspects of its behavior upon Xe irradiation.

Abstract: Influence of small additives of copper, silver and tin on the angle of wetting and work of adhesion of monocrystals of chlorides of potassium and sodium is considered. The nature of interphase interaction of limit of the section monocrystals of chlorides of sodium and potassium with additives of the specified metals is revealed.

Abstract: In an experiment conducted at the Tomsk synchrotron "Sirius", the photon yield of parametric X-ray radiation generated by 500 MeV electrons in a tungsten monocrystal in Bragg geometry has been studied. The (111) tungsten monocrystal, having a thickness of 1.7 mm and a surface mosaicity of not more than 80^², was oriented at the Bragg angle θ_B = 45^° to the direction of the electron beam. The photons were detected at the angle 2θ_B = 90° relative to the electron beam. A comparison of PXR angular distributions with calculations has been carried out with taking into account the actual conditions of the experiment.

Abstract: The dislocation structure and mechanical properties of Ni₃Fe single crystals with the short range order were investigated. The laws of the dislocation structure evolution of single crystals at different deformation axis orientations were analysed. Correlation of the dislocation structure evolution with the deformation stages for the single crystals with the deformation axis orientations [001], [11], [011] and [1.8.12] was established. The role of the slipping plane numbers in the substructure evolution was revealed.

Abstract: Non-agglomerated ammonium dimolybdate (ADM) monocrystals with large diameter and high dispersion has been prepared through reaction-evaporation-crystallization (REC) process using ammonium tetramolybdate and ammonia solution as reactants. The as-prepared ADM monocrystals were systematically characterized by x-ray powder diffraction, transmission-reflection optical microscope, Fourier transform infrared spectroscopy and TG-DSC thermal analysis. It is shown that the as-prepared ADM samples are disperse monocrystals with well grain distribution and geometric shape, which can well meet the quality requirements for the subsequent production of molybdenum powders.

Abstract: Monocrystal nano-sliver lamella were prepared by hydrothermal method with the precursor Ag₂C₂O₄ and the surface active agent polyvinyl alcohol (PVA). The influence of the dosage of PVA on the film thickness and yield of nano-sliver lamella (NSL) were analyzed. And the morphology, the film thickness and electron diffraction pattern of NSL were characterized by scanning electron microscopy (SEM) and transmission electron microscope (TEM) respectively . Furthermore,the same sample was respectively characterized by the parallel optical path and the focus optical path of X-ray diffraction (XRD), and the difference between the diffraction data of these two paths was compared. The results show that the dosage of PVA has significant effect on the thickness and yield of monocrystal nano-sliver lamella. The reason that the great difference between diffraction data of the parallel light path and focusing light path can be mainly owing to the preferential orientation in space of NSL.