Extensive research of conductivity in the fluorite-like KLnMoOF (Ln = La, Pr, Nd) rare earth molybdates: theoretical and experimental data.

The conductive properties of fluorite-like structures KLnMoOF (Ln = La, Pr, Nd: KLM, KPM, KNM) have been studied theoretically and experimentally. Theoretical studies included the geometrical-topological analysis of voids and channels available for migration of working ions; bond valence site energy calculations of the oxygen ions' migration energy; quantum-chemical calculations for the estimation of the oxygen vacancies formation energy. Experimental measurements of conductivity were made using impedance spectroscopy and as a function of oxygen partial pressure.

Catalytic Pyrolysis of Polystyrene Waste in Hydrocarbon Medium.

The fast catalytic pyrolysis of polystyrene in the hydrocarbon medium (light and heavy cycle oil) over zeolite catalysts at 450-550 °C was investigated. The influence of reaction conditions (medium, temperature, vapor residence time, polystyrene concentration) on polymer conversion and product distribution was studied. It was found that the polymer conversion is close to 100%, while ethylbenzene, benzene, and toluene are the main products of its transformation.

Crystal structure of bismuth-containing NdFe(BO) in the temperature range 20-500 K.

Neodymium iron borate NdFe(BO) is an intensively studied multiferroic with high electric polarization values controlled by a magnetic field. It is characterized by a large quadratic magnetoelectric effect, rigidity in the base plane and a rather strong piezoelectric effect. In this work, the atomic structure of (NdBi)Fe(BO) was studied by single-crystal X-ray diffraction in the temperature range 20-500 K (space group R32, Z = 3).

Flux growth, structure refinement and Mössbauer studies of FeGaBO single crystals.

High-quality FeGaBO single crystals (0.0 ≤ x ≤ 1.0) in the form of basal plates were synthesized by the flux technique.

Crystal structure and structural phase transition in bismuth-containing HoFe(BO) in the temperature range 11-500 K.

An accurate single-crystal X-ray diffraction study of bismuth-containing HoFe(BO) between 11 and 500 K has revealed structural phase transition at T = 365 K. The Bi atoms enter the composition from BiMoO-based flux during crystal growth and significantly affect T. The content of Bi was estimated by two independent methods, establishing the composition as (HoBi)Fe(BO).

Characteristic features of polytypism in compounds with the LaWO-type structure.

Crystals with the LaWO-type structure (6H and 5H polytypes) were obtained by a self-flux method from high-temperature solutions. Some of the crystal samples were studied by single-crystal X-ray structure analysis. The diffraction patterns indicated that two phases co-exist in each sample.

Crystal structure, phase transition and structural deformations in iron borate (YBi)Fe(BO) in the temperature range 90-500 K.

An accurate X-ray diffraction study of (YBi)Fe(BO) single crystals in the temperature range 90-500 K was performed on a laboratory diffractometer and used synchrotron radiation. It was established that the crystal undergoes a diffuse structural phase transition in the temperature range 350-380 K. The complexity of localization of such a transition over temperature was overcome by means of special analysis of systematic extinction reflections by symmetry.

Structure of fluorite-like compound based on Nd₅Mo₃O₁₆ with lead partly substituting for neodymium.

A single crystal of Nd5Mo3O16 with lead partly substituting for neodymium, which has a fluorite-like structure, was studied by precision X-ray diffraction, high-resolution transmission microscopy and EDX microanalysis. The crystal structure is determined in the space group Pn3¯n. It was found that the Pb atoms substitute in part for Nd atoms in the structure and are located in the vicinity of Nd2 positions.

X-ray diffraction study of oxygen-conducting compounds Ln₂Mo₂O₉ (Ln = La, Pr).

The La2Mo2O9 (LM) and Pr2Mo2O9 (PM) single crystals are studied using precision X-ray diffraction and high-resolution transmission microscopy at room temperature. The crystal structures are determined in the space group P2(1)3. La and Pr atoms, as well as Mo1 and O1 atoms, are located in the vicinity of the threefold axes rather than on the axes as in the high-temperature cubic phase.