The features of the propagation of an X-ray beam controlled by an adaptive X-ray optical element (AXOE) based on a monolithic bimorph bending actuator have been examined. An analysis of the spatial displacement of the X-ray beam, which occurs when a control signal is applied to the adaptive element, was performed using a two-dimensional detector mounted on a laboratory X-ray source. The positions of the X-ray focal point in space that occurs during the oscillations of the AXOE are determined for various parameters of the control signal. Besides, the positions of the adaptive element and the diffracted beam in space are described by equations. The obtained results can be used for X-ray diffraction studies with high locality.
A comprehensive study of the supramolecular organization and optical properties of floating layers and Langmuir–Schaefer (LS) films of an A2B-type subphthalocyanine derivative was performed. The molecular packing of target compound in monolayer structures on a water surface was simulated, and the unit cell parameters of the monolayer were calculated. Using Brewster angle microscopy data, it was shown that this compound forms stable and homogeneous layers with edge-on molecular packing at the air/water interface. The supramolecular organization of these floating layers is largely preserved during LS transfer: atomic force microscopy reveals thin films with an average thickness of approximately 1.2 nm, low roughness, and a very small number of 3D aggregates. Thus, the controlled deposition of LS films made it possible to obtain low-defect, homogeneous films of the studied subphthalocyanine derivative with adjustable thickness. Such supramolecular structures in LS films are promising for applications in optoelectronics, where controlled optical response and morphological homogeneity are required.
The study of Co45Fe45Zr10 nanoclusters in a thin MgF2 film was carried out using the grazing incidence small angle X-ray scattering (GISAXS) method. The scattering map of the thin (Co45Fe45Zr10)x(MgF2) _100 - x film was obtained at the PHASE beamline of the Kurchatov specialized source of synchrotron radiation “KISI-Kurchatov.” For its interpretation, the theory of scattering on a paracrystal has been developed, taking into account the refraction effects, and algorithms for processing the radial sections of the map have been developed. The analysis of the distortion of the diffraction ring has led to the conclusion that there is a difference in the lateral and normal distribution of Co45Fe45Zr10 nanoparticles in the MgF2 matrix.
The review covers the recent advances in the synthesis and applications of composite affinity adsorbents based on metal‑organic frameworks (MOFs) and biomolecules. These bio‑MOFs are shown to combine a high specific surface area, controlled porosity, adjustable surface chemistry, and the diversity of metals and ligands with the advantages of bioligands (antibodies, aptamers, peptides), such as high biocompatibility, low toxicity, chirality, the specific molecular recognition, and the ability to fine‑tune hydrophobic and hydrophilic properties. Particular attention is given to the potential of amino- and peptide-containing composite adsorbents as enantioselective materials and to the use of highly selective bioligands for the creation of hybrid adsorbents with exceptional selectivity. Such materials are shown to be promising for the selective extraction and concentration of both small molecules and biomacromolecules from complex matrices (environmental samples, food stuff, biological fluids). The further development of bio‑MOF composites will make it possible to design adsorbents characterized by a high selectivity, high extraction capacity, reproducibility, stability, and adaptability and will expand their application in analytical chemistry, biology, medicine, and ecology, with assessing their sustainability and economic efficiency.
Classifying isomorphism, V.M. Goldschmidt (1926) distinguished a aliovalent “space-filling isomorphism”. The example was the mineral yttrofluorite Ca_1–xY_xF_2 + x (1911). For its unexplored structure, a model of filling cubic voids of the CaF2 structure with superstoichiometric F1– located in their centers has been proposed. The model has been repeatedly confirmed by density measurements. In crystals Ca0.607Ce0.393F2.393 (1969) and Ca0.9Y0.1F2.1 (1970) studied by methods of structural analysis, the centers of cubic voids of the structure are not filled. The M_1–xR_xF_2 + x studied so far has been classified according to the defect of the anionic motif. The modern model of the defective structure of M_1–xR_xF_2 + x (M = Ca, Sr, Ba, Cd; R = Y, La–Lu) is based on octa-cubic clusters [ M_14–nR_nF_64 + n ] (n ≤ 14). Cluster types were distinguished by interstitial anions F(32f)3 and F(48i). A new approach to the M_1–xR_xF_2 + x defective structure is proposed. It assigns the role of the root cause of aliovalent “space-filling isomorphism” to R3+ cations. Without them, neither this type of isomorphism nor the formation of clusters is possible. The evolution of the cluster structure along the M_1–xR_xF_2 + x series is determined by the lanthanide contraction of 14 R = Ce–Lu with a 4f subshell, which affects the R3+ ionic radii.
