Synthetic magnetic opals

We present studies of novel nanocomposites of BiNi impregnated into the structure of opals as well as inverse opals. Atomic force microscopy and high resolution elemental analyses show a highly ordered structure and uniform distribution of the BiNi filler in the matrix. These BiNi-based nanocomposites are found to exhibit distinct ferromagnetic-like ordering with transition temperature of about 675 K. As far as we know there exists no report in literature on any BiNi compound which is magnetic.     

Investigation of the peculiarities of Ge island growth on Si (100) under MBE conditions

The results of investigating the features of Ge-island formation on Si (100) under conditions of molecular-beam epitaxy is presented. Nanosized structures at heteroboundaries (islets and quantum dots) are attracting great interest due to new useful properties and broad prospects of their application.     

Revelation of the microstructure of oxide FeAl/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> nanocomposite

The structural transformations at different stages of the preparation of oxide FeAl/Al₂O₃ nanocomposite by mechanosynthesis with the use of a preliminarily activated FeAl precursor are studied by means of transmission electron microscopy, X-ray diffraction and Mössbauer spectroscopy.     

Effect of drying temperature on sizes and morphology of goethite nanoparticles

The morphology, structure, and size distribution of goethite nanoparticles, which are obtained by chemical precipitation of iron salt and alkali in aqueous solutions with different surfactants and are dried at 100°C and room temperature, have been investigated in order to develop technology for obtaining goethite (α-FeOOH) nanoparticles of minimum sizes. It is found that the samples dried at a temperature of 100°C have a different phase state and increased sizes as compared to the samples dried at room temperature.     

Absorption spectrum of water as a reflection of charge diffusion

The absorption spectrum of liquid water in the range of 10³–10¹³ Hz (from dc conductivity of up to 5 THz IR resonance) is completely and uniformly described by a simple physical model. The model assumes the existence in water of a high concentration of H₃O⁺ and OH^? ions (up to 4.5% of the total number of molecules) that exchange protons with H₂O molecules on the scale of picoseconds.     

Radiation phenomena in microinhomogeneous structures of flouroaluminate glass-like materials

The simulation of the fluoroaluminate matrix with small additives of phosphates has made it possible to create low-scattering glasses with a wide transparency window in the infrared region and to study the fundamental problem on the formation of radiation defects typical for the phosphate matrix (PO ₃ ^2? hole, PO ₃ ^2? electron, and PO ₄ ^2? hole defects). By comparing the spectra of induced optical absorption, electron paramagnetic resonance, and Raman scattering, it has become possible to investigate the generation of defects in the course of the successive formation of the phosphate matrix in fluoroaluminate glass. The feasibility of the formation of PO ₄ ^2? hole centers both in single tetrahedra and upon rupture of P-O-P bridge bonds with the simultaneous formation of PO ₃ ^2? electron centers has been shown. As a result of the revision of the nature and mechanisms of formation of radiation color centers in the studied glasses, it appears promising to introduce cerium (Ce³⁺) and europium (Eu³⁺) as protectors into these glasses.     

Supramolecular structure of aqueous solutions of glucose according to dynamic light scattering data

The nature and structure of large-scale fluctuations in aqueous glucose solutions were studied by dynamic light scattering. The two-component model of solution was used. The supramolecular structure of the solutions was determined and their phase diagram at low concentrations was schematically constructed. The volume of clusters in solution was calculated.