Inorganic Materials (v.47, #14)
Total reflection X-ray fluorescence analysis: Physical foundations and analytical application (A review) by N. V. Alov (1487-1499).
The current state of the art in one of the most promising techniques of X-ray spectral analysis, namely, total reflection X-ray fluorescence analysis (TXRF), is summarized. The underlying physical processes, including reflection, refraction, total external reflection (TER) of X-rays, and formation of standing waves by TER, are considered. The construction and crucial components of a modern energy-dispersive TXRF spectrometer, involving X-ray tubes, monochromators, detectors, and reflectors, are described. Examples of analytical application of TXRF are given. High efficiency of this technique for qualitative and quantitative chemical analysis of liquids and solids of various natures is demonstrated. The main research trends in surface analysis and investigation of surface layers of solids by TXRF are discussed.
Keywords: X-ray fluorescence analysis; total external reflection of X-rays; chemical analysis; surface
Determination of Se, As, Sb, Te, and Bi in wastewaters of mining-and-processing integrated works with the use of AAS-ETA by V. I. Safarova; G. F. Shaidulina; T. N. Mikheeva; F. Kh. Kudasheva; N. R. Nizamutdinova (1500-1504).
The procedure of analysis of wastewaters of mining-and-processing integrated works on the content of Se, As, Sb, Te, and Bi with the use of an atomic absorption method with electrothermal atomizer, which involves the preliminary sample preparation and choice of temperature program, modifier, and corrector of nonselective absorption, was described. The conditions were matched for the determination of low concentrations of these elements in natural waters.
Keywords: atomic absorption analysis with electrothermal atomization; analysis of natural and waste waters; sample preparation; temperature-time program; correction of nonselective absorption; chemical modifiers; graphite cell; matrix effect; method of addition of standard sample; degree of detection
Direct integral-scintillation atomic-emission spectroscopic analysis of powder samples by V. N. Apolitskii (1505-1511).
The peculiarities of applying integral-scintillation atomic-emission spectroscopy for the study of powder samples in the case of their “spilling-blowing” into a multipolar arc discharge plasma are considered. Owing to the periodic short-term accumulations of analytical spectral signals, a large number of spectra for individual microportions of the sample are obtained. The sorting of the analytical spectral signals in accordance with the signal/noise ratio allows the scintillation signals from chemical elements under determination to be found; these signals are used in conventional calculations of the results; the other numerous signals are eliminated. This makes it possible to increase the signal/noise ratio during determination of elements present in low concentrations and to improve their detection limit. In order to detect scintillation signals, the duration of periodic short-term registration of spectral signals should be less than 100 ms, but not more than double the duration of scintillation signals. The use of short-term durations for accumulating signals, i.e., when the intensity of spectral lines is high, offers the possibility for determining high concentrations of chemical elements in samples. It is shown that the element composition can be determined without weighing samples by a special approach to estimating the results of analysis which involves the use of the ratio between the concentrations of chemical elements.
Keywords: atomic emission spectral analysis; scintillation; powder samples; “spilling-blowing” method
Methods of sample preparation of soil, bottom sediments, and solid wastes for atomic absorption determination of heavy metals by V. I. Safarova; G. F. Shaidullina; T. N. Mikheeva; F. Kh. Kudasheva; N. R. Nizamutdinova (1512-1517).
A comparative study of various methods of preparation of soils, bottom sediments, and solid wastes for atomic absorption analysis is performed. A procedure of AAS determination of metals in solid samples is proposed with the use of several methods of sample preparation: autoclave, microwave, ultrasound, and method of acidic extraction in open vessels. The recommended conditions of microwave decomposition are given for samples of soil, bottom sediments, rocks, and wastes of processing of copper sulfide ores.
Keywords: heavy metals; atomic absorption analysis; standard samples of soils; solid samples; sample preparation; acidic extraction; autoclave decomposition; acidic decomposition in open vessels; ultrasound decomposition; microwave decomposition
Effects of uncertainty of excitation condition on error of method of fundamental parameters in X-ray fluorescence analysis by B. D. Kalinin; R. I. Plotnikov; Yu. I. Sergeev (1518-1521).
The errors of the method of fundamental parameters in X-ray analysis due to deviation of device characteristics (anode voltage, angles of incidence of the primary radiation and the take-off the fluorescence, thickness of anodic coatings of X-ray tubes of the shot type, and purity of the exciting spectrum) from those used in the calculation of the nominal values are considered. It is shown that the contribution of these errors can reach 0.5–1 rel. % for the uncertainties in units of the fundamental parameters that are typical of X-ray equipment and for a significant difference in the composition of the analyzed and standard samples (particularly when “pure metals” and a nonlinear calibration functions are used as reference samples), which is especially important for high-precision determination of the main components.
Keywords: X-ray fluorescence analysis; method of fundamental parameters; binary systems; uncertainty of device characteristics; intensity and content error
Determination of lanthanum, cerium, neodymium, ytterbium, and yttrium in geological samples with the use of a multichannel analyzer of atomic emission spectra by N. L. Chumakova; E. V. Smirnova (1522-1528).
The procedure of atomic emission determination (with a photographic record of the spectrum) of yttrium and four rare-earth elements (La, Ce, Nd, and Yb) was modified on the basis of a multichannel analyzer of emission spectra (MAES) in geological samples of various contents. In addition to the increase in the rate of analysis, the detection limits were improved by a factor of two to three, correct calculation of the background was realized, and the errors of reproducibility of analysis were decreased. The validity of the results was confirmed by the comparison of the contents obtained with the accepted characteristics of the samples analyzed according to GeoPT program and with the data of MS-ICP analysis.
Keywords: atomic emission analysis; rare-earth elements; multichannel analyzer of spectra (MAES); standard samples; metrological characteristics
Broadening of linear dynamic range of photoelectric registration of emission spectra by Zh. P. Burmii; N. I. Zolotareva; V. A. Khvostikov; S. S. Grazhulene (1529-1533).
A method for broadening the linear dynamic range of measurements (LDRM) for a developed photoelectron system of registering emission spectra using series of charge-coupled devices (CCDs) was suggested. The method is based on creation of virtual spectrum scanning channels with different sensitivity and corresponding mathematical processing of measurement results. The possibility of increasing the LDRM by three orders of magnitude as compared with the standard scanning mode for different elements was shown by example of determination of admixtures in artificial mixtures based on graphite powder. Analysis of carbon nanopipes in wide range of content of impurity elements was performed using the obtained data.
Keywords: emission spectra; arc discharge; photoelectron registration; linear dynamic range
Gas chromatography/mass spectrometry analysis of arsine of high purity by V. A. Krylov; O. Yu. Chernova; A. Yu. Sozin; A. P. Kotkov (1534-1538).
The procedure of gas chromatography/mass spectrometry determination in arsine of high purity was described for impurities of permanent gases, carbon dioxide, C1–C5 hydrocarbons, and hydrides of groups 4–6 of Mendeleev’s periodic table of elements. The detection limits of impurities took values from 2 × 10−5 to 2 × 10−7 mol %.
Keywords: chromatography mass spectrometry; arsine of high purity; impurities; detection limit; validity
Determination of nickel and vanadium in crude oils by electrothermal atomic absorption spectrometry and inductively coupled plasma atomic emission spectroscopy after mineralization in an autoclave by E. M. Sedykh; L. N. Bannykh; G. S. Korobeinik; N. P. Starshinova (1539-1543).
A comprehensive technique for determining Ni and V in crude oils in a wide range of their concentrations is described. The procedure involves ETAAS, ICP-AES, and autoclave sample preparation. The optimal conditions for the mineralization of oil samples in Ankon-AT2 analytical autoclaves in a mixture of HNO3 and H2O2 are found. Oil and condensates of oil- and gas-bearing basins are taken as objects of investigation. The concentrations of Ni and V in these systems are estimated and the regularities in the distributions of Ni and V are revealed.
Keywords: crude oils; electrothermal atomic absorption spectrometry; inductively coupled plasma atomic emission spectroscopy; autoclave mineralization of organic samples
Analysis of refractory materials for metallurgy by the ICP-AES method by E. A. Tormysheva; E. V. Melikhova; T. N. Ermolaeva (1544-1547).
A technique for determining oxides of aluminum, iron (III), calcium, magnesium, and chromium (III) at a level of 2–205 μg/l by the ICP-AES method is described. The absence of the effect of components of the matrix (Al2O3, MgO) and fluxes (Na, K) used for decomposition of analyzable samples on the intensity of an analytical signal is shown. Methods of sample decomposition by alloying are compared depending on the composition of refractories.
Keywords: refractories; decomposition; alloying; atomic emission spectroscopy with induction-bound plasma
Determination of silicon and aluminum oxides in zeolites by V. N. Talanova; O. L. Lependina; A. G. Buyanovskaya; S. L. Dzvonkovskii (1548-1550).
Methods are described for determination of aluminum and silicon oxides in a broad range of their content. The aluminum oxide content varies from 1% to 50%, and the silicon oxide content varies from 50% to 99%. The methods are used for analysis of industrial zeolites and catalysts on their basis.
Keywords: X-ray fluorescence analysis of zeolites and catalysts on their basis; determination of silicon and aluminum oxides
Devices for local electrochemical analysis (Review) by V. V. Slepushkin; B. M. Stifatov; Yu. V. Rublinetskaya; E. O. Il’inykh (1551-1556).
A review of devices operating on the basis of local electrochemical analysis is presented. Theoretical fundamentals of design of electrochemical thickness gauges, phase analyzers, and other devices and fields of their application are considered. Metrological characteristics of the existing multifunctional devices are presented and prospects of their development are shown.
Keywords: local electrochemical analysis (LEA); electrochemical cell; electrochemical thickness gauge; phase analyzer
Photometric method of study of semiconductor heterostructures by S. G. Nikiforov (1557-1562).
The problems of diagnostics of the parameters of light-emitting diodes are considered. The method of study described is applicable for the study of degradation phenomena in any emitting structures and devices based on them, as well as in classical emitters, lamps (incandescent, luminescent, metal-halogen, and others). The method of study of degradation phenomena in semiconductor emitting heterostructures is based on measurements of the spatial distribution of luminous intensity by the goniophotometric method. By example of the technology of thermal ultrasound welding of contact conductors, the physical mechanisms affecting the degradation of characteristics of emitting dies and light diodes based on them are described. The ways of increasing the reliability and useful life of light-emitting diodes are demonstrated.
Keywords: degradation; luminous flux; spatial distribution of luminous intensity; thermal ultrasound welding; heterostructure
Analysis of anisotropy of properties on the basis of studies of texture of coarse-grained ingots of thermoelectric materials by V. T. Bublik; A. I. Voronin; E. A. Vygovskaya; V. F. Ponomarev; N. Yu. Tabachkova; O. V. Toropova (1563-1568).
An analysis of anisotropy of the properties of a Bi2Se0.3Te2.7 solid solution was carried out using construction of demonstrative surfaces for thermoelectric effectiveness and thermal expansion coefficients. It is shown that the texture is an important factor forming anisotropy of properties and technological fitness of ingots for manufacturing modules. Anisotropy of properties based on the studies of the ingot textures obtained using the float-zone method and Bridgman method (growing thermoelectric plates in a flat cavity) was studied.
Keywords: composition-structure-properties; thermoelectric materials; thermocells; thermoelectric parameters; solid solutions; bismuth telluride
X-ray fluorescent spectrometer with total X-ray reflection for studies of kinetics of thin film deposition by V. M. Raznomazov; V. O. Ponomarenko; N. M. Novikovskii; Yu. I. Velichko; A. P. Kovtun; R. V. Vedrinskii; D. A. Sarychev (1569-1573).
An X-ray fluorescent spectrometer with total X-ray reflection and minimum detection limit by zinc of n · 10−10 g is developed that allows performing analysis of elements from magnesium to uranium. This spectrometer is used to determine the elemental composition of Bi-Nd-Fe-O films grown on an Al2O3 single crystal (transparent sapphire, face 0001) in a gas-discharge sputtering chamber of a ceramic Bi0.95Nd0.05FeO3 target. It is shown that the spectrometer allows registering formation and growth of films starting from the sputtering time of 15 s.
Keywords: X-ray fluorescence analysis; total X-ray reflection; elemental composition; ultrathin films
Nondestructive diagnostics of nanoheterostructures with InGaN/GaN multiple quantum wells by thermal admittance spectroscopy by O. V. Kucherova; V. I. Zubkov; E. O. Tsvelev; I. N. Yakovlev; A. V. Solomonov (1574-1578).
On the basis of the designed complex of low-temperature admittance spectroscopy, the electron spectrum of semiconductor light emitting diode (LED) heterostructures with InGaN/GaN multiple quantum wells was investigated. The features of the construction of the measuring complex, as well as the technique of measurements of semiconductor nanoheterostructures and processing of admittance spectra, are presented.
Keywords: admittance spectroscopy; multiple quantum wells; InGaN/GaN
Method of electrical resistivity measurement for high-temperature melts by A. N. Shatunov; A. I. Maksimov; A. Yu. Pechenkov; I. V. Poznyak (1579-1583).
A contactless method of electrical resistivity measurement for high-temperature melts is described. The method is based on induction melting in split water-cooled crucible and solving the inverse problem of electromagnetic field with the use of the thermal and electrical parameters of an induction system. Results of the electrical resistivity measurement of a pure-grade aluminum oxide melt within the temperature range of 2300–2950°C in air are presented.
Keywords: contactless measurement; resistivity; induction melting; inverse problem; split water-cooled crucible; aluminum oxide
Regularities of application of glow discharge spectrometry for quantitative layer-by-layer analysis of thin coatings by G. S. Sprygin; K. V. Grigorovich; B. A. Shitov; V. I. Vlasova (1584-1591).
Regularities of application of glow discharge spectrometry are considered for quantitative layer-by-layer analysis of thin coatings on steels. The known methods of surface analysis used in industry and in research are compared. The main fields of application of glow discharge spectrometry are considered. The key causes for distortion of the analytical signal shape in quantitative layer-by-layer analysis using glow discharge spectrometers are discussed: the effect of the etching pit shape, analytical noise, and regularities of surface geometry of the studied samples. The main limitations of the methods in analysis of thin layers and coatings are shown. Calibration samples are developed for control of the thickness of thin chromium electrochemical coatings on steels. Metrological characteristics are estimated in measurement of the coating thickness. A method of quantitative layer-by-layer analysis on SA-2000 and GDS 850A glow discharge spectrometers (LECO) is proposed.
Keywords: glow discharge; layer-by-layer analysis; spectrometer; coating; calibration; plasma parameter; support
Effect of microalloying of copper with yttrium on its structure and mechanical properties by N. V. Kamyshanchenko; M. I. Durykhin; A. V. Gal’tsev; I. M. Neklyudov; B. V. Borts; S. V. Shevchenko (1592-1595).
The influence of microalloying of copper of MV grade with yttrium on its macrostructure and mechanical properties is studied. It is shown that small amounts of yttrium refine the structure of the alloy ingot and lead to additional purification of copper from impurities. Alloying of copper with yttrium significantly changes the fine structure of the material, which significantly affects the strength characteristics.
Keywords: alloying; yttrium; macrostructure; microhardness; mechanical properties; physical properties
Increase in the exactness of measurement of physical parameters of high-temperature superconductor materials by V. I. Pudov; A. S. Sobolev (1596-1599).
A procedure for estimating the critical temperature T c and width ΔT c for the superconducting transition of high-temperature superconductor materials based on plotting the first derivative of the temperature correlation dependence of the electrical resistance of a sample is developed. The critical point of the derivative corresponds to T c , and its width at half-height corresponds to ΔT c . The procedure provides a decrease in the relative error of estimation of T c and ΔT c for qualitative samples by a factor of 1.7–2.
Keywords: procedure; estimation; high-temperature superconductor material; critical temperature T c ; super-conducting transition ΔT c
Testing of materials on corrosion-cyclic crack resistance in water at increased temperatures by E. A. Grin’ (1600-1603).
An experimental plant for testing materials on corrosion-cyclic crack resistance in water with increased parameters and methodological peculiarities of such tests are described. The technological system of the plant represents a circuit of natural circulation of water medium with the temperature mode in the working chamber up to 275°C. The length of a developing crack in the sample was determined by the change in compliance; this required producing a special sensor for measuring linear displacements. A diagram of corrosion-cyclic crack resistance of steel 22K obtained from experimental results in water of the ammonia mode (pH 9) at 275°C is shown.
Keywords: experimental plant; methodology; circulation circuit; test chamber; corrosive medium; temperature; exhaust; crack resistance; displacement sensor; metal; kinetic diagram
Studies of deformation properties of single-crystal material based on zirconium dioxide with application of photoelastic coatings by G. V. Moskvitin; M. V. Bortnikov; M. S. Pugachev; A. F. Mel’shanov (1604-1607).
A technique of studying deformation properties on the basis of single crystals of partially stabilized zirconium dioxide using the method of photoelastic coatings is described. Linearity and elasticity of the material samples are studied under their compression up to destruction. The main mechanical characteristics of the material are presented.
Keywords: polarization optical method of photoelastic coatings; single-crystal nanostructured material; zirconium dioxide; supersolid material
Ultimate plasticity—the universal local fracture criterion for lifetime prediction of welded structures by A. S. Kurkin; G. P. Batov (1608-1617).
A method is presented of the modeling of material fatigue destruction on the basis of a ductile fracture criterion—ultimate plasticity as a function of stress 3-axity. The criterion enables one both to determine the number of cycles until the fatigue crack initiation from the stress concentrator and to predict the character of its growth. The condition of reliability of results is high accuracy of finite element modeling with geometric and physical nonlinearity taken into account. The criterion is applicable for stress concentrators of different sharpness. The local character of the criterion makes it suitable for inhomogeneous material properties, as well as for thermally loaded structures.
Keywords: modeling; destruction; ultimate plasticity; crack growth