[en] The particular capabilities of a high-resolution continuum source absorption spectrometer were exploited to the determination of halogens in an ordinary air-acetylene flame. In the first part of the studies, a simple method was developed, which allows the determination of fluorine by measuring GaF molecular absorption. The molecules are generated in the presence of an excess of Ga in the flame. Under such conditions, all fluorine is converted into GaF, yielding an evaluable signal for the fluorine determination. Molecular bands of GaF were found between 211 and 214 nm; the strongest absorption band head at 211.248 nm was examined in detail to prove its applicability to analytical measurements. To this end, potential chemical and spectral interferences were tested, using various highly concentrated acids and metallic salt solutions. Since no serious interferences were found, the new method proved to be very reliable. As limit of detection, 1 mg L^-1 fluorine in the presence of 10 g L^-1 Ga was achieved, using a measurement time of five seconds. The linear dynamic range covers more than three orders of magnitude. Accuracy and precision were verified by analysis of a standard reference material (BCR No. 33)

[en] The atomic structure of crystals of ZnInF₅x7H₂O has been established and the crystal structure of CdGaF₅x7H₂O adjusted on the basis of three-dimensional X-ray diffractometry data obtained at room temperature. The H atoms are localized on the difference synthesis of the electron density. The adjustment is accomplished by the least squares method with an allowance for the anisotropy of thermal vibrations of the atoms and the effect of secondary extinction and anomalous scattering to divergence factors of 1.6 and 2.4%, respectively. The peculiarities of the atomic structure of these compounds and the hydrogen bonds in them are discussed

[en] The effect of gallium fluoride introduction on optical properties, density was investigated in zirconium fluoride based glasses. IR spectra and Raman effect spectra were demonstrated. Experimental data were correlated with chemical analysis results. Gallium fluoride introduction was demonstrated to decrease density and refractive index of fluorozirconate glass. Gallium fluoride introduction was assumed to increase coherence of fluorozirconate frame, in this case gallium was as a glass former

[en] Effect of B³⁺ ion substitutions in Rb₂RB³⁺Fe(B³⁺:Ga, Sc) structure compounds on the pattern of phase transformations is studied. Dependences of parameter of cubic cell of transformation temperature on concentration of substitute atoms and on dimensions of trivalent ion (Rb³⁺₎ are determined

[en] The potential energy curves (PECs) of the ³Π states of GaX (X = F, Cl, and Br) molecules are calculated using the multireference configuration interaction method with a large contracted basis set aug-cc-pV5Z. The PECs are accurately fitted to analytical potential energy functions (APEFs) using the Murrell—Sorbie potential function. The spectroscopic parameters for the states are determined using the obtained APEFs, and compared with the theoretical and experimental data available presently in the literature. (atomic and molecular physics)

[en] The structure of fluoride glasses on the basis of GaF₃ and InF₃ is studied. The glass lattice bond, i.e. its uniformity or nonuniformity, was analyzed through introduction of alkali metal (LiF, NaF, RbF, CsF) into the composition of fluoride glasses. The consecutive replacement of a modification by alkali metal fluorides made it possible to establish the nonuniformity of the glass-forming lattice by studying through the NMR ¹⁹F method. It may be confirmed by comparing the fluorine ions dynamic behavior in the glasses, based on the indium and gallium trifluorides, that the glass fluorine subsystem on the In basis is more mobile

[en] The discovery of fluoride glasses has shown that these materials are an excellent media for ultralow loss transmission of audio and visual information. Recently, it has been found that In F_3- based systems have more stable compositions and present better optical properties when compared to fluoride glasses from other systems. Several compositions in the pseudo-ternary system In F_3- Gd F_3- Ga f₃ with (20% Zn F₂ - 20% Sr F₂ 2% Na) have been investigated, which appear very stable concerning devitrification. Therefore, these glasses seem to be very promising for the fabrication of special optical fibers.(author)

[en] Analysis of specific features of the Raman spectrum of zirconium tetrafluoride base glasses has been performed using the percolation theory. It permitted suggesting a model of grid formation for the given of glasses in a wide concentration range. It is shown that in the range of the glass-forming agent from 33 mol.% and higher a unified branched cluster is formed, its structure being determined by the composition of the glass-forming complex. The results obtained are confirmed by NMR data on fluorozirconate glass study

No abstract available

[en] For the first time, the Franck-Condon factors and r-centroids, which are very closely related to vibrational transition probabilities, have been evaluated for the bands of A³Π⁺₀ - X^l Σ⁺, B³ Π^-₁ - X^l Σ⁺, and C¹Π - X^l Σ⁺ systems of Ga F and In F molecules. A numerical integration procedure is followed to evaluate these transition probability parameters, using a suitable potential. (Author)