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The review primarily considers the scientific progress in the identification of impurities, molecular compounds, and heterophase inclusions in high-purity sulfur. Methods for their determination, established by the present time, based on atomic emission spectrometry, mass spectrometry, colorimetry, gravimetry, titrimetry, turbidimetry, conductometry, gas chromatography, infrared spectrometry, chromatography–mass spectrometry, and laser ultramicroscopy are thoroughly characterized. [ABSTRACT FROM AUTHOR]

In this paper, we examine the purity level and impurity composition of the titanium, zirconium, and hafnium samples at the Exhibition–Collection of Extrapure Substances and present estimates of the average and total concentrations of elemental impurities in the purest samples. We examine the impurity composition of the array of the group 4 elements and contributions of particular groups of impurities and discuss the purity level of the group 4 elements and their compounds manufactured in Russia and abroad. [ABSTRACT FROM AUTHOR]

In this paper, we examine the purity level and impurity composition of rare-earth metals represented at the Exhibition–Collection of Extrapure Substances and present estimates of the average and total concentrations of elemental impurities in the purest samples. We analyze the impurity composition of the entire array of rare-earth metals and contributions of particular groups of impurities. [ABSTRACT FROM AUTHOR]

Glassy chalcogenides AVBVI obtained by solidification of high-temperature melts inherit the polymolecular nature of the melt. The influence of this circumstance on the optical properties of glasses is important for the fabrication of optical fibers and has not been adequately studied. Bulk samples of high-purity As40 –xS60 +x glasses (0 < x < 5) containing less than (1–2) × 10–5 wt % metal and silicon impurities and not more than (0.5–1) × 10–4 wt % carbon, oxygen, and hydrogen compounds were manufactured, and optical fibers were fabricated from these materials. The IR spectra of 12 cm-long bulk samples and optical fibers of up to 15 m length were recorded in the 1000–2000 cm–1 spectral range. The spectra of the bulk samples and the optical fibers showed absorption bands with maxima at 1950, 1805, 1460, and 1320 cm–1, due to the presence of super-stoichiometric amount of sulfur in the glass. The corresponding extinction coefficients were determined. The results of the study indicate that the stoichiometry of As2S3 can be considered as a factor significantly affecting the optical characteristics of glass. [ABSTRACT FROM AUTHOR]

This paper presents additional data on carbon, hydrogen, and oxygen impurities in molecular form in extrapure selenium. Using gas chromatography/mass spectrometry analysis, selenium has been shown for the first time to contain hydrocarbons, halogenated hydrocarbons, and sulfur- and selenium-containing substances. Forty-six elemental impurities were detected in selenium by inductively coupled plasma atomic emission spectroscopy. Data on carbon-, oxygen-, and hydrogen-containing molecular impurities in commercially available extrapure selenium will be helpful in choosing and optimizing methods for its further ultrapurification. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the purity level of the alkali metals and their compounds manufactured in Russia and abroad. We consider the impurity composition of the array of and individual alkali metals in the Exhibition–Collection of Extrapure Substances and contributions of particular impurity classes. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the purity level of the alkaline-earth metals (AEMs) and their compounds manufactured in Russia and abroad. We consider the impurity composition of the array of AEM samples in the Exhibition–Collection of Extrapure Substances and contributions of particular groups of impurities. [ABSTRACT FROM AUTHOR]

We have studied glass formation and located the boundaries of the glass-forming region in the TeO2–MoO3–Pr2O3 system. The results demonstrate the possibility of obtaining glasses containing up to 30 mol % PrO1.5. Optical characteristics of the transmission spectra of the glasses have been calculated. [ABSTRACT FROM AUTHOR]

TeO2–ZnO–MoO3 glasses containing cobalt(II) ions in the concentration range from 0.035 to 1.2 wt % have been prepared using orthotelluric acid, ammonium heptamolybdate, zinc nitrate, and cobalt(II) nitrate as starting materials. In the wavelength range from 0.42 to 3.0 μm, the transmission spectra of the glasses contain two strong absorption bands, peaking at ~584 and ~1357 nm. Using a series of glasses doped with 3.5 × 10–2 to 1.2 wt % cobalt, the specific absorption coefficient of Co2+ ions has been determined (3550 ± 210 dB/(km ppm) at 584 nm) and its spectral dependence has been obtained in the wavelength range studied. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the impurity composition of high-purity oxide samples in the Permanent Exhibition–Collection of Extrapure Substances. We estimate the average and total concentrations of elemental impurities in the purest samples and their arrays and assess the contributions of individual impurity classes to the total impurity concentration, which makes it possible to more accurately characterize statistical characteristics of the impurity composition of the high-purity oxides. [ABSTRACT FROM AUTHOR]

4.9–5.5 µm laser oscillations were observed in high-purity bulk terbium-doped Ge36Ga5Se59 glass pumped by pulsed 2.93 µm Er:YAG laser. This is the first evidence of laser action corresponding to 7F5–7F6 transition of Tb3+ ions and of mid-infrared lasing in chalcogenide glass host. [ABSTRACT FROM AUTHOR]

In this paper, we discuss general aspects of the impurity composition of high-purity glass samples in the Permanent Exhibition–Collection of Extrapure Substances. We estimate the average and total concentrations of elemental impurities in the purest samples and assess the contributions of individual impurity classes to the total impurity concentration, which makes it possible to more accurately characterize the impurity composition of high-purity oxide and nonoxide glasses of various systems and the statistical characteristics used to describe it. [ABSTRACT FROM AUTHOR]

In this paper, we discuss general aspects of the impurity composition of high-purity solid halides, which are exemplified by an array of samples in the Permanent Exhibition–Collection of Extrapure Substances. We estimate the average and total concentrations of elemental impurities in the purest samples and assess the contributions of individual impurity classes to the total impurity concentration, which makes it possible to more accurately characterize the impurity composition of solid halides and statistic characteristics used to describe it. [ABSTRACT FROM AUTHOR]

(TeO2)0.70(ZnO)0.30 tellurite glasses doped with Cr3+ ions in the concentration range 80 to 2500 ppm have been prepared via melt solidification using orthotelluric acid and zinc nitrate, and their optical transmission has been measured in the wavelength range 0.3 to 2.7 μm. Transmission spectra of the glasses have been shown to contain two strong absorption bands, peaking at 460 and 650 nm. Using a series of glasses differing in chromium content, we have evaluated the spectral dependence of the specific absorption coefficient for the glasses, which has been shown to be 142 ± 2 cm–1/wt % at the maximum of the 650-nm absorption band. [ABSTRACT FROM AUTHOR]

This paper presents results of physical and computational experiments aimed at gaining insight into the behavior of silica impurity particles in two flowing contacting glass melts (core and cladding melts in the arsenic sulfide fiber drawing process). It has been shown that the particles present in the cladding melt are uniformly distributed, without passing into the core melt or concentrating at the interface between the two layers of the fiber. Theoretical calculations have been confirmed by experimental data. [ABSTRACT FROM AUTHOR]

Abstract—: In this paper, we discuss general aspects of the impurity composition of natural monoisotopic substances, which are exemplified by samples in the Permanent Exhibition-Collection of Extrapure Substances. The entire set of natural monoisotopes is divided into subsets belonging to sets of alkali and alkaline-earth metals, transition metals, rare-earth metals (REMs), and p-block elements. We estimate the average and total concentrations of elemental impurities in subsets of the purest samples of the natural monoisotopes. The purest monoisotopes are those of the p-block elements. Next are samples of the alkali and alkaline-earth metals, transition metals, and REMs. We estimate the contributions of individual impurity classes to the total impurity concentration, which enables more accurate characterization of the impurity composition of the natural monoisotopes and statistical characteristics of its description. [ABSTRACT FROM AUTHOR]

This paper examines sources of carbon impurities in polycrystalline monoisotopic 28Si prepared by a hydride method. Analytical data on the concentrations of carbon-containing impurities in volatile silicon compounds (28SiH4 and 28SiH4), process gases (Ar and H2), and polycrystalline 28Si are used to identify the major sources of carbon in the polycrystalline 28Si prepared by the hydride method. These are the starting 28SiH4 and calcium hydride used in 28SiH4 conversion into 28SiH4. The rate of carbon intake into polycrystalline silicon from the apparatus material during the monosilane pyrolysis process does not exceed 9 × 1011 cm-2 h-1. Polycrystalline silicon has been precipitated from monosilane with different concentrations of hydrocarbon impurities. At hydrocarbon concentrations in the range 10-4 to 10-3 mol %, the carbon concentration in the monosilane correlates with that in the silicon obtained from it. High-purity monosilane has been used to prepare polycrystalline 28Si samples with concentrations of carbon impurities in the range (0.8-2.3) × 1015 cm-3. Based on calculations of the carbon impurity distribution along the length of a zone-refined ingot, we examine the effect of the initial carbon concentration in the starting polycrystal on the yield of single-crystal monoisotopic 28Si. Requirements are formulated for the carbon concentration in polycrystalline 28Si which ensure a high yield of single crystals with parameters suitable for metrological applications. [ABSTRACT FROM AUTHOR]

The concentration of hydroxyl groups in different types of quartz glass tubes, the OH concentration profile across the tube wall, and the kinetics of OH removal during heat treatment in the temperature range 750-950°C have been studied by Fourier transform IR spectroscopy. For TK-I tubes, produced by vacuum electromelting of quartz, followed by annealing in a hydrogen atmosphere, we have calculated the diffusion coefficient of OH groups in this temperature range and the activation energy for diffusion: 215 ± 10 kJ/mol. We have found heat treatment conditions that ensure a considerable decrease in the concentration of OH groups in quartz tubes that are used in the fabrication of reactors for the preparation of extrapure chalcogenide glasses. [ABSTRACT FROM AUTHOR]

Using iron pentacarbonyl distillation as an example, we analyze the vaporization process in a closed vaporization-condensation system where vapor condenses on a flowing down liquid film. We jointly analyze the mechanisms behind vaporization, vapor transport, condensation, and flowing of the condensate on the inner surface of a vertical tube. We calculate the thickness of the flowing down liquid film, determine the vaporization coefficient for a closed system using experimentally determined temperature dependences of the vaporization rate and saturated vapor pressure, and present the vaporization rate as a function of the vaporization and condensation temperatures, the radius and height of the condensation tube, and the vaporization area of the still residue. [ABSTRACT FROM AUTHOR]

The motion of two viscous melts and the behavior solid-doped nanoparticles is studied using advanced computational techniques of fluid dynamics, taking into account the temperature inhomogeneity of the stream and the influence of the surface tension on the melt-particle-melt interface. The results of the application of the developed method for the system of chalcogenide glasses and silicon dioxide nanoparticles are given. [ABSTRACT FROM AUTHOR]

We have calculated the total elemental composition and assessed its statistical characteristics for two classes of high-purity volatile substances--inorganic hydrides and chlorides--using Exhibition-Collection of Extrapure Substances data. The average and total contents of elemental impurities in the purest samples of compounds of these classes have been estimated. Using the division of elemental impurities into classes, we have estimated the contributions of individual classes to the total impurity content in arrays of hydride and chloride samples. The use of these calculation techniques makes it possible to more accurately characterize the impurity composition of individual samples and arrays of samples on the whole, refining statistical characteristics of the description of the impurity composition. [ABSTRACT FROM AUTHOR]

We have determined the molecular composition of organic impurities in extrapure sulfur obtained by the distillation purification of sulfur recovered from gaseous hydrocarbons. Using vacuum extraction, we obtained a concentrate of impurities highly volatile compared to the major component. Gas chromatography/ mass spectrometry analysis indicated the presence of impurities in the form of hydrocarbons with up to eight carbon atoms and their thio, oxy, and nitro derivatives. The detection of this group of impurities accounts for the distinctive features of the preparation of sulfur with low carbon and oxygen contents through ultrapurification of gas-derived sulfur. [ABSTRACT FROM AUTHOR]

This paper presents a mathematical model for the ultrapurification of substances in a closed vaporization-condensation system, where the evaporation rate is determined by the combined effect of the mechanisms behind vaporization, condensation, and vapor transport from the vaporization surface to the condensation surface, and the impurity distribution in the liquid is determined by the diffusion mechanism. The degree of purification is evaluated as a function of the vaporization and condensation temperatures and the main simple distillation apparatus design parameters by numerical simulation for a particular example: removal of barium impurities from selenium. [ABSTRACT FROM AUTHOR]

This paper describes a mathematical model for the behavior of impurity nanoparticles in two flowing contacting melts which takes into account the surface tension forces on the interface between the melts. The nanoparticle distribution in a bilayer cylindrical melt flow is shown to be significantly influenced by the diffusion mechanism and surface tension forces. The proposed calculation procedure is applied to AsS-AsS (core-cladding) glasses and silica nanoparticles. [ABSTRACT FROM AUTHOR]

A procedure is developed for the determination of benzothiophene, dibenzothiophene, and 4,6-dimethyldibenzothiophene in high-purity sulfur, including liquid-phase microextraction preconcentration, identification by gas chromatography−mass spectrometry, and gas chromatographic determination with flame photometric detection. The rate of microextraction recovery was from 16 to 78%. The limits of detection were 8 × 10 wt % for benzophiophene and 2 × 10 wt % for dibenzothiophene and 4,6-dimethyldibenzothiophene. [ABSTRACT FROM AUTHOR]

This paper discusses correlations in the impurity composition of the purest solid group 13-16 elemental substances so far, exemplified by a set of samples in the Exhibition-Collection of Extrapure Substances, a permanent exhibition. The abundance of particular elemental impurities in the samples of the high-purity substances has been determined. Dividing the entire set of impurities into classes, we have accurately determined integral characteristics (average and total concentrations) of impurities in the samples and evaluated the contribution of each impurity class to the total impurity concentration. [ABSTRACT FROM AUTHOR]

Data are presented on the purity of the samples of elemental substances, including isotopically enriched samples, received by the Exhibition-Collection of Extrapure Substances in 2007-2015. During this time period, the permanent exhibition received 26 samples of elemental substances from 11 institutes and research and production centers of Russia. The first samples of high-purity isotopically enriched silicon, germanium, sulfur, and selenium were provided. The total impurity concentration in the best samples is 3 × 10 to n × 10 at %. More than half of the new samples compare well to the current world level. [ABSTRACT FROM AUTHOR]

The impurity composition of SiH, SiH, and SiH silanes and GeH, GeH, GeH, and GeH germanes isotopically enriched to above 99.9 at % has been studied by gas chromatography/mass spectrometry using capillary adsorption columns. Impurities have been identified by comparing their mass spectra with NIST data and information available in the literature, and by inferring their structure from fragment ions and retention times. We have identified 53 impurity substances in silanes and 42 in germanes: permanent gases; saturated, unsaturated, halogen-containing, and aromatic C-C hydrocarbons; their homologues; alkyl derivatives of silane and germane; chlorogermane; siloxanes; fluorosiloxanes; sulfur compounds; and dioxane. The silicon- and germanium-containing impurities have been shown to be isotopically enriched, as the major component. The detection limits of the impurities are 5 × 10 to 3 × 10 vol %, comparing well with the best results in the literature. [ABSTRACT FROM AUTHOR]

The article contains a survey of methods of deep purification of elemental arsenic and its compounds used in technology of optical, optoelectronic, and semiconductor materials. Severe requirements on permissible impurity content (ppb level) and features of structure and properties of these substances make the process of their production in the state of high purity unescapably multistage. The physics and chemistry and factors determining efficiency of the developed processing routes and the attained purity level for the arsenic, its oxide, chloride, hydride, and sulfides are described in this paper. [ABSTRACT FROM AUTHOR]

We have prepared (TeO)(MoO) glass samples containing 0.01 to 0.11 wt % chromium and determined their optical transmission in the range from 450 to 2800 nm. The glasses have been shown to have a strong absorption band centered at 660 nm. From the attenuation coefficient as a function of Cr concentration in the glasses, we have evaluated their specific absorption coefficient, which has been shown to be 190 ± 2 cm/wt % at the maximum of the absorption band. [ABSTRACT FROM AUTHOR]

The contact angles of the quartz glass surface by the AsS and AsSe glass melts and surface tension of these glass melts in the temperature range of 325-370°С have been experimentally measured. The polytherms are linear and possess negative slope in the mentioned temperature range. The work of the adhesion of AsS and AsSe glass melts to the quartz glass surface has been calculated and compared to the data on the adhesion strength of the AsS-SiO and AsSe-SiO boundaries of the solid phases. [ABSTRACT FROM AUTHOR]

This paper considers the evaporation process in an evaporator-connecting tube-condenser system under conditions such that the evaporation rate is determined by the evaporation and condensation mechanisms and the hydraulic resistances of the evaporation and condensation compartments and connecting tube. We present a mathematical model and numerical simulation results that demonstrate quantitative patterns of a steady-state evaporation process in a closed evaporation-condensation system. For a particular example of selenium vacuum distillation, we have determined the evaporation coefficient of selenium from experimental data on the temperature dependences of the selenium evaporation rate and saturated vapor pressure. [ABSTRACT FROM AUTHOR]

Adhesion of As-S and As-Se glasses to silica glass is studied by means of the steady detachment method. The results demonstrate that the adhesion strength of the boundary of solid phases increases with the content of chalcogens in the composition of glass. It is found that adhesion of arsenic sulfide glasses with sulfur content over 65% to silica glass exceeds the tensile strength of the silica glass during the process of solidification and annealing of chalcogenide preforms. The adhesion of arsenic chalcogenides to silica glass is determined to be the reason of chalcogenide glass contamination by heterophase inclusions. [ABSTRACT FROM AUTHOR]

We have carried out thermodynamic modeling of the GaI-S and ZnI-S systems by the method of equilibrium constants and calculated the chemical compositions of the condensed and vapor phases in the temperature range 200-500°C. Our experimental data demonstrate the feasibility of preparing zinc thiogallate by reacting gallium(III) iodide and zinc(II) iodide with sulfur. Synthesis was carried out at a temperature of 450°C over a period 2 h, followed by calcination of the product at 650°C in order to remove the residual iodine. The practical ZnGaS yield was 92-94%. [ABSTRACT FROM AUTHOR]

A new technique in which the entire set of impurities in a substance is represented as a set of impurity classes has been developed for estimating the most likely and total concentrations of elemental impurities in samples of high-purity substances. Estimates of the purity of samples with the use of this technique have lower random and systematic errors in comparison with estimates without impurity classification. It has been shown that estimates of the integral characteristics of individual impurity classes in the total set of samples allow one to find the expectation of the total concentration for impurity classes which are represented in particular samples only by detection limits. The results are illustrated by the example of the rare-earth oxide samples in the Exhibition-Collection of Extrapure Substances. [ABSTRACT FROM AUTHOR]

We present a mathematical model and results of computational experiments aimed at investigating multipass zone refining kinetics based on the concept of average impurity concentration in the ingot portion being refined and demonstrate that ultrapurification of an ingot at a small molten zone length has an induction period. Using stepwise optimization of zone recrystallization with a molten zone length varying from pass to pass, we find a zone length control function that minimizes the number of zone passes needed to ensure a given purity level. [ABSTRACT FROM AUTHOR]

The thermophysical and structural characteristics of high-purity monoisotopic Se containing 99.9 at % main isotope were studied. Differences were found in properties between monoisotopic selenium and selenium of the natural abundance of isotopes, which had comparable chemical purities and identical thermal histories. [ABSTRACT FROM AUTHOR]

We have prepared (TeO)(MoO) glass samples containing 0.01-0.3 wt % copper and investigated their optical transmission in the wavelength range from 450 to 2800 nm. In this spectral region, the glasses have a strong absorption band centered at 830 nm. From the dependence of radiation attenuation on copper concentration in the glasses, we have evaluated the specific absorption coefficient of Cu in the range 600-2800 nm. It has been found to be 108 ± 1 cm/wt % at the maximum of the 830-nm absorption band. [ABSTRACT FROM AUTHOR]

This paper examines a mathematical diffusion model for the purification of substances by distillation. We present the dependences of the separation factor-a quantitative characteristic of the degree of purification of substances-and the effective separation coefficient on the Peclet number, vaporization rate, and sampling ratio. For selenium containing barium impurities, we determine the equilibrium separation coefficient and diffusion coefficient of the solute from experimental data. [ABSTRACT FROM AUTHOR]

Data are presented on the influence of silver and sodium ions on the refractive index and structure of TeO-WO-LaO glasses. Using ellipsometry, we have obtained dispersion dependences of the refractive index of the tellurite glasses. Structural changes in the glass network have been assessed using the Wemple-DiDomenico model. Increasing the mole fraction of NaO from 3 to 12% increases the refractive index of the glasses by 4%, whereas increasing the mole fraction of AgO from 5 to 12% at NaO content of 3% increases the refractive index by 1%. [ABSTRACT FROM AUTHOR]

We have investigated the coprecipitation of tellurium(IV) and tungsten(VI) compounds through the addition of aqueous ammonia to a mixture of a tellurium dioxide solution in hydrochloric acid and tungstic acid. We have revealed general trends in the distribution of macrocomponents between the precipitate and solution and demonstrated the feasibility of proportional tellurium(IV) and tungsten(VI) precipitation in the pH range from 2 to 7. [ABSTRACT FROM AUTHOR]

We have investigated the coprecipitation of tellurium(IV), molybdenum(VI), and lanthanum(III) hydroxides from hydrochloric acid solutions of compounds of these elements and found conditions under which the precipitate was identical in composition to the starting solution of macrocomponents. [ABSTRACT FROM AUTHOR]

We have prepared (TeO)(MoO) tellurite glass samples containing 0.02-0.5 wt % nickel and investigated their optical transmission in the range 450-2800 nm. The transmission spectra of the glasses contain absorption bands centered at 810 and 1320 nm. From the composition dependence of the absorption coefficient, we have evaluated the specific absorption coefficient of Ni in the range 600-2800 nm. It has been found to be 20.6 ± 0.4 cm/wt % at the maximum of the 1320-nm absorption band. [ABSTRACT FROM AUTHOR]

Precipitates of tellurium(IV), molybdenum(VI), and bismuth(III) compounds of controlled composition have been obtained by precipitation from hydrochloric acid solutions of tellurium dioxide, ammonium heptamolybdate, and dibismuth trioxide. We have examined the general aspects of the macrocomponent distribution between the precipitate and solution and found conditions of a sufficiently complete tellurium(IV), molybdenum(VI), and bismuth(III) precipitation in a weakly acidic medium. After drying and calcination, the precipitates thus obtained were used as starting mixtures for the preparation of TeO-MoO-BiO glasses. [ABSTRACT FROM AUTHOR]

This paper describes a 3D laser ultramicroscopy technique and apparatus for the nondestructive characterization of heterophase inclusions in bulk high-purity materials for fiber and power optics. In this technique, the concentration and size of inclusions undetectable by optical microscopy are determined using CCD detection of the light scattered by them in a direction normal to the incident laser beam at wavelengths from 0.63 to 0.98 μm. The detection limit of the technique in terms of inclusion size is n × (10-100) nm, the range of detectable number concentrations is 1-10 cm, and the scan depth in the sample is ∼1 cm. Its performance has been evaluated using test systems. The potential of the technique is illustrated by the dispersion analysis of promising materials for IR fiber-optic applications. [ABSTRACT FROM AUTHOR]

Adhesion between AsS glass and quartz glass has been studied by a uniform pull-off method. The pull-off stress for the adhesion of glassy AsS to quartz glass has been determined as a function of temperature in the temperature range 110-190°C. The results demonstrate that, in the case of AsS glass, the adhesion strength increases exponentially with increasing test temperature and exceeds 2500 kPa at the glass transition temperature. We have studied how the adhesion strength is influenced by the contact temperature and time, tension test temperature, and quartz glass surface roughness. [ABSTRACT FROM AUTHOR]

The article discusses the study on the synthesis of monoisotopic 73GeH4 and 74GeH4 monogermanes with ≈99.9 percent isotope and chemical compounds' chemical elements of 10–5 mol %. The study involves monogermanes synthesis featuring their quantification of impurity composition and deep purification. Result shows that the content of impurities in the monogermanes does not surpass to 10–5 mol %.

This paper describes a process for the preparation of extrapure gallium(III) sulfide by reacting gallium(III) iodide with sulfur in an evacuated two-zone quartz glass reactor. The maximum synthesis temperature was 350°C. The residual iodine was removed by calcining the powders at temperatures from 500 to 650°C. The gallium(III) sulfide yield was 93-96% of theoretical yield. The samples were characterized by X-ray microanalysis, X-ray diffraction, and laser mass spectrometry and were shown to contain the following impurities (ppm): silicon, 20-28; iron and calcium, 0.5-0.6; potassium, 0.3-0.7; chromium, 0.2; chlorine, 70-100; aluminum, 0.05-0.1; and phosphorus, 0.1-2. The iodine content varied from 0.04 to 1.8 at %, depending on calcination temperature and time. [ABSTRACT FROM AUTHOR]

We have assessed interlaboratory and between-method discrepancies in the certification of standards of high-purity nanomaterials and precursors and analyzed the dependence of the discrepancy on the impurity concentration (an important factor, influencing the discrepancy value) and analytical method. [ABSTRACT FROM AUTHOR]

We have studied novel materials promising for fiber-optic applications: composites in the form of AsS glass containing Cr-doped zinc chalcogenide particles. Their dispersion characteristics and optical properties have been investigated in relation to preparation conditions. Process parameters have been found that enable the fabrication of optical fibers possessing luminescence properties. [ABSTRACT FROM AUTHOR]