Compensation for the Influence of Fluctuations in the Distance to the Object During Noncontact Probing in Spectral Domain Optical Coherence Tomography

Radiophysics and Quantum Electronics - We propose and experimentally test a numerical method for correction of the influence of fluctuations in the distance to objects during noncontact probing in...     

Pressure- and temperature-induced valence tautomeric interconversion in a o-dioxolene adduct of a cobalt-tetraazamacrocycle complex

An electronic switch at the molecular level has been realized by using a class of ionic compounds of the formula [Co(L)(diox)]Y (L = tetraazamacrocyclic ligand, Y = mononegative anion). Such compounds undergo temperature- and pressure-induced intramolecular one-electron transfer equilibria. The transition temperature of interconversion varies with the nature of the counterions Y (Y = PF6, BPh4, I). Surprisingly the effect of the anion on the transition temperature is not only governed by its volume but also by its coulombic interaction.     

Elimination of Artifacts Caused by the Nonidentity of Parallel Signal-Reception Channels in Spectral Domain Optical Coherence Tomography

Radiophysics and Quantum Electronics - We study the causes of artifact appearance in the images obtained by the method of spectral domain optical coherence tomography with parallel reception of the...     

Structure and mutual transformations of anhydrous and hydrous CsMgPO4

A complex study of the synthetic CsMgPO₄ phosphate with a ??-tridymite structure type is performed. It is found that CsMgPO₄ is an unstable phase. At room temperature in air, it absorbs water and turns into the CsMgPO₄ · 6H₂O crystal hydrate. The transformation of cubic CsMgPO₄ · 6H₂O into orthorhombic CsMgPO₄ proceeds upon heating to 150°C by the pattern of the first-order phase transition with the dehydration of the specimen.     

New Crystals in the CsHSO4–CsH2PO4–NH4H2PO4–H2O System

Crystallography Reports - The phase equilibria in the CsHSO4–CsH2PO4–NH4H2PO4–H2O four-component aqueous salt system have been studied. The crystallization ranges and solubilities...     

Synthesis of new material compositions with special properties under impact-dynamic conditions

This study examines the problems of creating new structural forms under impact-dynamic influence of ionic metal beams on a surface in order to expand the functional properties of iron construction materials. We investigated potential applications under various extreme environmental conditions (corrosion and radiation resistance, thermal stability) to evaluate physical and chemical processes that give rise to new properties which are different from equilibrium conditions for synthesized iron-based composites that include surface alloy compositions. The synthesis of composites was carried out in a vacuum installation equipped with an electroarc evaporator. Double surface iron composite alloys were synthesized using microplasma technology. Penetration depth of the ions of group IV-VI metals into iron was estimated using Monte Carlo methods to model binary collisions. This estimation was consistent with the results of the local X-ray spectrum analysis. Nuclear gamma resonance and local X-ray spectrum analysis was used to assess transformation of the structure of the alloyed materials into new structural forms, changing their properties.     

Synthesis and immobilization of molecular switches onto titaniumdioxide nanowires

The precursor [Fe^III(L)Cl (L = N,N′-bis(2′-hydroxy-3′-methyl-benzyliden)-1,7-diamino-4-azaheptane) is combined with [Mo(CN)₈]^4? yields a star shaped nona-nuclear cluster, [Mo^IV{(CN)Fe^III(L)}₈]Cl₄. This Fe₈Mo molecule is a high-spin system at room temperature. On cooling to 20 K some of the iron(III) centres in the molybdenum(IV)-star switch to the low-spin state as proven by Mössbauer spectroscopy. This molecule was deposited on TiO₂ nanowires by electrostatic interactions between the cluster cations and the surface functionalized titanium oxide nanowire. The synthesis and surface binding of the multistable molecular switch was demonstrated using IR and UV–Vis spectroscopy (high-resolution) transmission electron microscopy ((HR)TEM) and Mössbauer spectroscopy. High- and low-temperature Mössbauer spectra indicate that the spin state transition of the free cluster molecules is preserved after surface binding. The above results emphasize the possibility of fabricating molecule-based low-dimensional structures by using traditional bottom-up approaches based on the electrostatic interaction between the cluster cations and polymer functionalized nanowires. These results can be generalized for the application to both charged and non-charged molecules.     

Spin-crossover and liquid crystal properties in 2D cyanide-bridged Fe(II)-M(I/II) metalorganic frameworks

Novel two-dimensional heterometallic Fe(II)-M(Ni(II), Pd(II), Pt(II), Ag(I), and Au(I)) cyanide-bridged metalorganic frameworks exhibiting spin-crossover and liquid crystal properties, formulated as {FeL(2)[M(I/II)(CN)(x)](y)}·sH(2)O, where L are the ligands 4-(4-alkoxyphenyl)pyridine, 4-(3,4-dialkoxyphenyl)pyridine, and 4-(3,4,5-trisalkoxyphenyl)pyridine, have been synthesized and characterized. The physical characterization has been carried out by means of EXAFS, X-ray powder diffraction, magnetic susceptibility, differential scanning measurements, and Mo?ssbauer spectroscopy. The 2D Fe(II) metallomesogens undergo incomplete and continuous thermally induced spin transition at T(1/2) ≈ 170 K and crystal-to-smectic transition above 370 K.