Publications by authors named "Nikolay I Chkhalo"

The paper considers the possibility of using the diamond-silicon carbide composite Skeleton with a technological coating of polycrystalline silicon as a substrate for X-ray mirrors used with powerful synchrotron radiation sources (third+ and fourth generation). Samples were studied after polishing to provide the following surface parameters: root-mean-square flatness ≃ 50 nm, micro-roughness on the frame 2 µm × 2 µm σ ≃ 0.15 nm.

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Over the next decade, the extremely brilliant fourth generation synchrotron radiation sources are set to become a key driving force in materials characterization and technology development. In this study, we present a conceptual design of a versatile "Materia" diffraction and imaging beamline for a low-emittance synchrotron radiation facility. The beamline was optimized for operation with three main principal delivery regimes: parallel collimated beam ∼1 mm beam size, micro-focus regime with ∼10 μm beam spot size on the sample, and nano-focus regime with <100 nm focus.

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Correction for 'Depth-resolved oxidational studies of Be/Al periodic multilayers investigated by X-ray photoelectron spectroscopy' by Niranjan Kumar , , 2023, , 1205-1213, https://doi.org/10.1039/D2CP04778K.

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The quantification of surface and subsurface oxidation of Be/Al periodic multilayer mirrors due to exposure in the ambient atmosphere was investigated by depth-resolved X-ray photoelectron spectroscopy. The contribution of oxidation was lower for the thicker layer of Al in the periodic structures since the surface was less chemically reactive for the oxidation. This was investigated by finding the depth-resolved slope of the intensity ratio of metal/oxides (Be/BeO and Al/AlO) by analyzing the chemical shift of Al 1s and Be 1s photoelectrons.

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Microstructural properties of the beryllium (Be) and silicon (Si) in periodic multilayer mirrors Be/Si with the variation of film thickness were comprehensively determined by Raman scattering. For the thinner films, the structure of Be evolved in the amorphous phase, and it was transformed into the polycrystalline phase for thicker films. The Si films in the periodic structure were condensed into the amorphous phase.

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In the present paper, the formation of an interface region in the multilayer periodic Mo/Be structure with/without a BC or Si barrier layer depending on the annealing conditions was studied using X-ray photoelectron spectroscopy. The formation of different beryllides at the interfaces Be-on-Mo and Mo-on-Be was explained by the impact of the deposition-induced exchange caused by ballistic collisions and surface free energy. The influence of the high temperatures on the thermal stability of Mo/Be multilayer systems without/with a barrier layer was studied.

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In periodic W/Be multilayers, thickness-dependent microstructural and phase modifications were investigated in W and Be layers. In X-ray diffraction, α-W was predominant for the ultrathin layer of W, while β-W evolved along with the α-W phase for higher film thickness. For the thicker layers, the thermodynamically metastable β-W vanished and a single well-defined preferably oriented stable α-W phase was observed.

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The phonon and plasmon excitations and electronic properties of interfaces of periodic W/Si and Si/W multilayer structures were investigated. The Boson band originated from quasilocal surface acoustic phonons for ultrathin Si layers, excited by Raman scattering. In confined Si layers, a small fraction of crystalline Si nanoclusters were embedded within a large volume fraction of amorphous Si (a-Si) nanoclusters.

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In the present study, the formation of intermediate compounds in the Mo/Si multilayer was realized by the introduction of barrier layers at the interfaces. Their impact on the interdiffusion of Mo and Si was analyzed via X-ray photoelectron spectroscopy. It was established that the insertion of a thin Be barrier layer led to the formation of beryllide MoBe12 at the interface Si-on-Mo, which prevented the formation of molybdenum disilicide and improved the interface.

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We present an approach adapted to study the interface (composition and extension) of X-ray multilayer mirrors using angle resolved photoelectron spectroscopy (ARXPS). In the approach we rely on the concept of the average effective attenuation length (EAL) of the photoelectron and not on the inelastic mean free path (IMPF), which allows us to take into account the contribution of elastically scattered electrons and to increase the accuracy of the determined thickness of the layers. We apply the developed approach to study the formation of interfaces in a multilayer periodic Mo/Si mirror.

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Multilayer normal-incidence mirrors allow the numerical aperture (NA=0.3-0.5) of a projection lens to be significantly increased in the spectral ranges of the water (λ = 2.

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