Cylindrically bent diamond single-crystal plates have a great potential for creating energy dispersive spectrometers and focusing crystal monochromators. When they are designed, it is necessary to take into account the significant stresses that appear on bending the plates. The strain tensor and the elastic stress fields in a cylindrically bent single-crystal (110) diamond plate are calculated. The calculations are based on experimental data obtained by local Laue diffraction. The calculation results can be used to design new X-ray optical devices with the ability to control their parameters.

In this study, a new series of phosphors, Ca9−xZnxGd0.9(PO4)7:0.1Eu3+ (x = 0.00−1.00, step dx 0.05), was synthesized, consisting of centro- and non-centrosymmetric phases with β-Ca3(PO4)2-type structure. Crystal structures with space groups R3c (0.00 ≤ x < 0.35) and R3¯c (x > 0.8) were determined using X-ray powder diffraction and the method of optical second harmonic generation. In the region 0.35 ≤ x ≤ 0.75, phases R3c and R3¯c were present simultaneously. Refinement of the Ca8ZnGd(PO4)7 crystal structure with the Rietveld method showed that 71% of Gd3+ ions are in M3 sites and 29% are in M1 sites. A luminescent spectroscopy study of Ca9−xZnxGd0.9(PO4)7:0.1Eu3+ indicated the energy transfer from the crystalline host to the Gd3+ and Eu3+ luminescent centers. The maximum Eu3+ luminescence intensity corresponds to the composition with x = 1.

Insufficient information on the diffraction and energy-dispersion properties of elastically bent diamond limits its range of application in X-ray optics. Laue micro-beam diffraction has excellent potential for studying these properties. With this method, we explained the origin of the Laue spots asterism, calculated the strain–stress fields generated due to the bending of the diamond plate, and determined the bending radius in situ with high accuracy. The method can be used to control the dispersion characteristics of bent plates by changing the x-ray beam diameter or bending radius. Important conclusions are drawn for practical application of bent diamonds.

The lack of information on the diffraction and energy dispersive properties of elastically curved thin single-crystal diamond plates limits their application in X-ray optics. To study these properties in a cylindrically curved diamond plate with a thickness of 40 mu m and (110) surface orientation, we used the Laue microdiffraction method, which is highly informative, since it allows one to obtain a diffraction pattern in various crystallographic directions. Bending of the plate leads to the asterism of Laue spots due to the inclination of the Bragg planes and the presence of deformation of the crystal lattice. A detailed analysis of the diffraction pattern made it possible to formulate the conditions under which the asterism of the Laue spots equally depends on the inclination of the crystallographic planes and deformation. This opens up the prospect of using the Laue method to visualize strain fields and determine their maximum values in various crystallographic directions in diamond single crystals with a cylindrical bend. It has been demonstrated that the participation of the AgK alpha 1 and AgK alpha 2 characteristic lines in the diffraction makes it possible to determine in situ the bending radius of the plate. It is shown that a curved diamond plate is a dispersing element in a wide energy range. It has been established that by changing the bending radius of the plate and the diameter of the X-ray beam, it is possible to control the energy-dispersive characteristics. The results of the studies carried out can be used to create elements of X-ray optics intended for operation in high-power beams of modern synchrotron sources and X-ray lasers. The high structural perfection of a single-crystal diamond plate makes it suitable for work with coherent X-rays.

Cylindrically bent diamond single-crystal plates have a great potential for creating energy dispersive spectrometers and focusing crystal monochromators. When they are designed, it is necessary to take into account the significant stresses that appear on bending the plates. The strain tensor and the elastic stress fields in a cylindrically bent single-crystal (110) diamond plate are calculated. The calculations are based on experimental data obtained by local Laue diffraction. The calculation results can be used to design new X-ray optical devices with the ability to control their parameters.

The recent start of the European X-ray Free-Electron Laser (EuXFEL) provides a unique pulsed X-ray source of high spectral brilliance and high photon flux at a high repetition rate and opens the possibility for new scientific opportunities. However, the EuXFEL beam has a high peak power that is converted into a high cyclic thermal load on the optical elements, such as mirrors and monochromators, and is impossible to fully mitigate within the pulse train pattern. In the single crystal based X-ray monochromators, the increase of temperature leads to deformation of the crystal structure which affects the rocking curve and consequently the performance of these devices and the quality of the transmitted X-ray beam. To address the increase of temperature, we propose the use of a diamond channel-cut monochromator as an alternative to the current silicon monochromators. In this work we present the design and parameters of the diamond monochromator, heat load simulations and the surface and crystalline quality characterisation. The heat load simulations indicate a high performance of the monochromator under the pulse train of the EuXFEL and the characterisation demonstrates high crystal quality and its functionality as a double crystal monochromator.

Herein, the high‐quality large‐sized single‐crystalline diamond successfully grown by the chemical vapor deposition (CVD) technique is demonstrated. The structure perfection of this diamond is comparable with that of the best diamond single crystals grown by the temperature gradient method under high pressure and high temperature. In addition, CVD diamonds contain far fewer metallic impurities. The high structural quality of this diamond is unambiguously confirmed by the observation of interferrometric fringes (Kato fringes) without any defects in the section X‐ray diffraction images of the areas of 3 × 3 × 1.5 mm 3 size. Moreover, the full width at half maximum of the double‐crystal rocking curves (400) Bragg reflection from defect‐free areas of the diamond is close to theoretical. The nitrogen‐enriched 100 μm‐thick intermediate layer between the substrate and the growing crystal provides avoidance of the defect inheritance of the 1b substrate for homoepitaxial growth. The high‐quality diamond single crystals grown by the CVD method pave the way for application as X‐ray optic elements suitable for operation in high‐power beams of new generation synchrotrons and X‐ray free‐electron lasers.

The mechanochemically synthesized Cu–20 wt % Al alloys are studied by the X-ray diffraction analysis and scanning electron microscopy. It is shown that, after 20 min of mechanical activation, the single-phase intermetallic compound Cu 9 Al 4 with crystallites ~3 nm in size, low microstrains (~0.03%), and particle size in the range from 0.2–0.4 to 2–4 μm is formed. The morphological characteristics of the solid solution of aluminum in copper, which has been mechanochemically synthesized from the Cu–10 wt % Al alloy, are studied. It is demonstrated that the solid solution is composed of platelike particles 10–50 μm in planar size and 2–10 μm in thickness. The scanning electron and optical microscopy data show that the Cu(Al) solid solution produced by the spark plasma sintering at 700°С are characterized by the low residual porosity (<0.5%). The Vickers hardness is 290 ± 30 HV.

X-ray diffraction analysis is used to study the mechanochemical formation of a solid solution in the Cu–10 wt % Al system. The formation of the solid solution is shown to occur via the formation of the CuAl2 and Cu9Al4 intermetallic compounds, which, in the course of mechanical activation, react with residual copper to form the Cu(Al), solid solution of aluminum in copper. Under the conditions of mechanical activation in a high-energy planetary ball mill, the two-phase product of the mechanochemical synthesis, namely, 90 wt % Cu(Al) + 10 wt % Cu9Al4 forms is formed. It is shown that the maximum reached Al concentration in the solid solution is 7.4 wt %. The microstresses of the solid solution are ~1%; the crystallite size reaches 35–40 nm.

We report the influence of an ultrathin Ru bottom electrode on ferroelectric properties of fully atomic layer deposition (ALD)-grown Hf0.5Zr0.5O2 (HZO) and La-doped Hf0.5Zr0.5O2 (HZLO)-based ferroelectric capacitors. We show that the Ru bottom electrode deposited by radical enhanced ALD (REALD) improves the remanent polarization of both capacitors considerably. The origin of such a phenomenon is established by grazing-incidence and symmetrical θ–2θ x-ray diffraction measurements. HZO films on Ru exhibit the orthorhombic phase, which is highly (002)-textured in the out-of-plane direction as compared to HZO on TiN. HZLO films demonstrate the rise of (111) intensity of the orthorhombic phase when it is grown on Ru. Both types of capacitors with Ru exhibit a lower wake-up degree as compared to the ones with TiN, which is assumed to be due to the difference in the bottom interface properties. At the same time, both HZO and HZLO on Ru suffer from the relatively early breakdown during electric field cycling, which is presumably due to the high surface roughness of REALD Ru. Taking into account the continuous search for the new precursor's chemicals and ALD processes for Ru, which would be able to provide smother films, ALD Ru might be promising for the hafnium oxide-based ferroelectric random access memory.

A method for the preparation of film coatings of titania doped with bismuth (Bi3+) and lead (Pb2+) ions, separately and simultaneously, has been developed based on sol–gel synthesis. According to X-ray phase analysis, the films represent a single-phase system of titania in anatase modification. It has been shown that doping of titania with bismuth and lead leads to a shift of the absorption maximum to the visible light region; in this case, the largest shift is observed in the sample containing 2.5 wt % bismuth and lead. The film coatings have been studied as catalysts of photoelectrooxidation of methanol, formic acid, and phenol. It has been shown that the highest catalytic effect is observed for the samples containing simultaneously bismuth and lead; however, doping of titania with bismuth has the greatest effect on the rate of organic substrates oxidation. It has been assumed that photoelectrochemical oxidation of the model systems with visible light is due to a decrease in the band gap of doped titania to 2.7 eV.

A method of formation of film coatings of titanium dioxide doped by bismuth ions (Bi 3+ ) is developed on the basis of sol–gel synthesis and used to form film coatings of titanium dioxide with the anatase structure on the photoanode surface. Thus, samples containing 0.5 to 20 wt % of Bi are obtained. It is shown that the doping of titanium dioxide by bismuth ions results in a shift of light absorption to the visible region of electromagnetic radiation spectrum. The absorption level depends on the concentration of bismuth and reaches its maximum for samples containing 0.5 and 1.0 wt % of Bi. It is suggested on the basis of the data of X-ray phase analysis that an increase in the content of bismuth to 20 wt % leads to destruction of crystalline regions and amorphization of bismuth oxide and titanium oxide. The obtained coatings are studied as catalysts of photoelectrocatalytic oxidation of formic acid under illumination by monochromatic and visible light. It is found that the highest catalytic effect is observed on samples containing 1.0 wt % of bismuth. The forbidden gap width is estimated on the basis of absorption of monochromatic (464 nm) light, and it is shown that photoelectrocatalytic oxidation of formic acid in the visible spectral range accompanied by formiate ion adsorption on the illuminated photoanode surface is probably due to a decrease in the forbidden gap width in doped titanium dioxide to 2.7 eV.

Abstract Onion-like carbon (OLC) particles were produced as a byproduct of thermal partial oxidation of methane under different O2/Natural Gas (NG) ratio. It was established that the particles have quasi-spherical morphology and concentric shell structure. The particles have an outer diameter of 20–60 nm while the inner cage is rather typical for onions and has a diameter below 1 nm. The concentric graphitic structure and spherical symmetry along with the absence of amorphous carbon were confirmed by transmission electron microscopy, electron diffraction, EDX spectroscopy and Raman investigation. Variation of O2/NG ratio was proved a powerful tool for controlling OLC particles yield and structure. The formation of single-core or multicore OLC can be controlled by thermal partial oxidation process.

We demonstrate the process of mechanical polishing of a single crystal diamond substrate to a roughness of no > 0.5 nm. We used the anisotropy of the polishing intensity depending on the crystallographic orientation of the diamond substrate relative to the rotation direction of the cast iron grinding wheel (scaife). The surface distortions and its roughness were measured by atomic force microscopy (AFM) and X-ray reflectometry (XRR). The proposed technique optimization allows preparation of ultra-smooth surfaces in a relatively short time of < 10 min.

Here we demonstrate performance of an original lab system designed for testing of X-ray parabolic compound refractive lenses (CRL) manufactured from a high-quality single-crystalline synthetic diamond grown by the high-pressure high-temperature technique. The basic parameters of a diamond CRL comprised from 28 plano-concave lenses such as the focal length of 634 mm, transmissivity of 0.36, field of view of similar to 1 mm and resolution of 6 mu m have been determined. Usually such measurements are performed on synchrotron radiation facilities. In this work characterization of CRL was performed by means of instruments and components that are available for laboratories such as the Rigaku 9kW rotating anode X-ray generator, the PANalytical parallel beam X-ray mirror, a 6 m long optical bench, high precision multi-axis goniometers, high resolution X-ray emulsion films, and ultra-fast high-sensitive X-ray area detector PIXel3D. Developed setup was used to find differences between experimental and design parameters, which is very important for the improvement of CRLs manufacturing technology.

A new type of a high-brilliance X-ray source known as the Thomson X-ray laser-electron generator (TXG) opens new possibilities for materials characterization by X-ray diffraction methods such as high resolution X-ray diffractometry and topography and diffraction analysis at extreme conditions in shear diamond anvil cells. The advantages of the TXG compared to X-ray laboratory sources are a high flux, a quasi-monochromatic, nearly parallel beam and a tunable wavelength. The paper presents examples of applications as well as estimations of typical photon flux and exposure time saving advantages resulted from an implementation of TXG radiation in a home laboratory.

Quality of a refractive compound X-ray lens can be limited by imperfections in surfaces of unit lenses and stacking precision. In general case both the lens transmission and optical aberrations define properties of a beam in the lens exit plane; together they can be expressed in terms of the generalized pupil function. In this work we measure this function for a diamond single crystal compound refractive lens. Consequently, we apply the pupil function to evaluate the performance of the examined compound refractive X-ray lens. A number of practically important conclusions can be drawn from such analysis.

In this work chemical and electrical properties of TiN films, grown by low temperature plasma-enhanced atomic layer deposition (PE-ALD) process from TiCl4 and NH3, were investigated. Electrical resistivity as low as 250Ohmxcm, as well as the lowest Cl impurity content, was achieved at 320 degrees C. Full-ALD Hf0.5Zr0.5O2-based metal-ferroelectric-metal capacitor with TiN electrodes was fabricated and its electrical properties were investigated. It was also shown that the proposed PE-ALD process provides an early film continuity, which was confirmed by ultrathin fully continuous film growth. Such ultrathin (3nm) and fully continuous TiN film was also successfully implemented as the top electrode to Hf0.5Zr0.5O2-based ferroelectric capacitor. Angle-resolved X-ray photoelectron spectroscopy (AR-XPS) was used for its thickness determination and a visible wake-up effect in underlying Hf0.5Zr0.5O2 layer was clearly observed.

In this work a double-crystal setup is employed to study compound refractive lenses made of single-crystal diamond. The point spread function of the lens is calculated taking into account the lens transmission, the wavefront aberrations, and the ultra-small-angle broadening of the X-ray beam. It is shown that, similarly to the wavefront aberrations, the ultra-small-angle scattering effects can significantly reduce the intensity gain and increase the focal spot size. The suggested approach can be particularly useful for the characterization of refractive X-ray lenses composed of many tens of unit lenses.