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A brief description of the concept of a soft X-ray microscope for the Nanoscope station, which is planned to be installed at the SKIF fourth-generation synchrotron, is given. The microscope is designed to study the structure of cells and dynamic processes in them with nanometer spatial resolution. It will use a unique absorption contrast of ~15 between carbon-containing structures and water in the spectral range of the water window, λ = 2.3–4.3 nm, which eliminates the need for contrasting and the use of fluorophores and minimizes the doses of ionizing radiation absorbed in the samples to obtain high-quality 3D images. The scanning and projection schemes of the microscope, their main technical characteristics, including the calculated spectra and parameters of the undulator source are presented, and an estimate of the absorbed doses depending on the resolution is obtained. The main advantage of the proposed concept lies in the use of an objective lens of high-aperture multilayer X-ray mirrors, which makes it possible to clearly visualize the focal section of the sample. Technically simple axial tomography will also be used to reconstruct the three-dimensional structure of frozen or dried samples. In the scanning scheme, due to a low dose of radiation, it will be possible to study living plant cells with a resolution of up to 10 nm, animals with a resolution of up to 80 nm, and cryofixed samples with a resolution of up to 5 nm. In the projection scheme, due to simultaneous observation of the entire focal XY section, the time for obtaining three-dimensional images is significantly reduced, but due to a large dose, it will be oriented mainly on the study of fixed samples. [ABSTRACT FROM AUTHOR]

Our and others' results on the thermal expansion of compounds and the crystal-chemical information about their structure have been used to properly select compositions of new NASICON materials with small thermal expansion and low thermal expansion anisotropy: MM′Ti(PO) (M and M′ are alkali metals, 0 ≤ x ≤ 1), M″FeTi(PO) (M″ is an alkaline-earth metal), and CaFeTi(PO) (0 ≤ x ≤ 1). Such materials have been synthesized through salt coprecipitation from aqueous solutions and their thermal expansion has been assessed by high-temperature X-ray diffraction. We have determined their unit-cell parameters as functions of temperature and correlated their thermal expansion parameters and composition. The KRbTi(PO) and RbCsTi(PO) materials obtained combine small volumetric thermal expansion and near-zero thermal expansion anisotropy. [ABSTRACT FROM AUTHOR]

The temperature dependence of the heat capacity of crystalline barium zirconium phosphate C = f( T) was measured over the temperature range 6-612 K. The experimental data obtained were used to calculate the standard thermodynamic functions C( T), H°( T) − H°(0), S°( T), G°( T) − H°(0) over the temperature range from T → 0 to 610 K and standard entropy of formation at 298.15 K. The data on the low-temperature (6 ≤ T/K ≤ 50) heat capacity were used to determine the fractal dimension of BaZr(PO). Conclusions concerning the topology of the structure of phosphate were drawn. Thermodynamic properties of MZr(PO) (M = Ca, Sr, Ba) were compared. [ABSTRACT FROM AUTHOR]

Complex phosphates of titanium, chromium, and metals(2+) of the general formula M0.5(1 + x )Cr x Ti2 − x (PO4)3 (M = Mg, Ca, Mn, Ni, Sr, Ba, and Pb) were synthesized. Their phase formation was studied by means of X-ray powder diffraction, electron probe microanalysis, differential thermal analysis, and IR spectroscopy. Individual phases and solid solutions crystallizing in kosnarite and langbeinite structure types were identified; their crystallographic parameters were calculated. The catalytic properties of phosphates Ca0.5(1 + x )Cr x Ti2 − x (PO4)3 in methanol conversion were studied. [ABSTRACT FROM AUTHOR]

The temperature dependence of the heat capacity of crystalline nickel zirconium phosphate C°p = f( T) was measured over the temperature range 6–664 K. The experimental data obtained were used to calculate the standard thermodynamic functions of Ni0.5Zr2(PO4)3 from T → 0 to 664 K. The standard entropy of phosphate formation from simple substances at 298.15 K was calculated from the absolute entropy of the compound. The data on the low-temperature heat capacity were used to determine the fractal dimension of Ni0.5Zr2(PO4)3 over the temperature range 30–50 K. Conclusions concerning the heterodynamic characteristics of the structure of Ni0.5Zr2(PO4)3 were drawn. [ABSTRACT FROM AUTHOR]

New complex phosphates of titanium, iron, and alkaline-earth metals have been synthesized. X-ray powder diffraction, differential thermal analysis (DTA), and IR spectroscopy are used to study phase formation in the series of M0.5(1+ x)FexTi2− x (PO4)3 (M = Mg, Ca, Sr, Ba) phosphates. Individual compounds and solid solutions are found to crystallize in the NaZr2(PO4)3 and K2Mg2(SO4)3 structure types. Their crystal parameters are calculated. CaFeTi(PO4)3 is studied using Mössbauer spectroscopy. Its structure is refined by the Rietveld method: space group $$R\bar 3$$ c, Z = 6, a = 8.5172(1), Å, c = 21.7739(4) Å, V = 1367.91(4) Å3. [ABSTRACT FROM AUTHOR]