X-ray phase analysis

X-ray phase analysis is used for identification of mineral phases of rocks, soils, clays, or mineral industrial material. The phase analysis of clays is particularly difficult because these materials generally consist of a mixture of different phases, like mixed and individual clay minerals, and associated minerals, such as calcite and quartz. Placon and Drits proposed an expert system for the identification of clays based on x-ray diffraction (XRD) data [45]. This expert system is capable of identifying associated minerals, individual clay minerals, and mixed-layer minerals. It can further approximate structural characterization of the mixed-layer minerals and can perform a structural determination of the mixed-layer minerals by comparison of experimental x-ray diffraction patterns with calculated patterns for different models. The phase analysis is based on the comparison of XRD patterns recorded for three states of the sample dried at room temperature, dried at 350°C, and solvated with ethylene glycol. 

The identification of associated minerals is performed by the ASSOCMIN module on all diffraction peaks in which the positions and intensities do not change after glycolation or heating. The observed data are compared with data from the most commonly associated minerals that are stored in the system. Results for the found minerals are displayed, and the user has to finally make the decision whether the result is useful or not. 

The identification of individual clay minerals is done with the module INDV-CLAY, which allows the user to select a clay mineral from a list for phase analysis. When a clay mineral is selected, the module displays the main features of the XRD pattern, its behavior after heating or ethylene-glycol treatment, and the minerals that 

The determination of the mixed-layer clay minerals is done by the NATMIX module, which makes decisions based on the comparison of the three states — dried, heated, and solvated. The comparison is based on rules that allow predictions to be made for the different types of mineral layers due to the different behavior in the three states. The system also proposes adding additional specific experiments that further refine the characterization of the layer composition. The system covers the entire family of mixed-layer clay minerals and determines their nature. 

Other modules support the structural characterization of the mixed-layer minerals. The STRUCMIX module determines the mean abundance of each layer and the range of interaction between these layers. CALCMIX proposes experimental data for reflections located in different diffraction domains and allows the nature and structure of the mixed-layer minerals to be confirmed by calculating theoretical XRD patterns and matching them with the experimental pattern. 

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The individuality of received complexes was proved by X-ray phase analysis (DRON-3.0). Preparative investigation of complexes was made. Infrared spectrums of complexes were made (Uh-20, KBr). It was proved that in the III complex hydroxylamine is coordinated with Fe (II) by oxygen in the form of n-oxyde-o-NH -and in IV - by nitrogen in the form of NH OH. The composition of IV hasn t been proved in dry ruminant because of surplus age of reagent. Tire composition of III responds to formula of [Fe(NH,OH) Cl,]. 

To begin with, we followed the procedure as described by Warkentin [4] for the synthesis of Prl2. The maximum temperatures reported were 1000 °C and 850°C, much higher than the peritectic transformation, I-ia-ProPrl2 at 758°C [1]. X-ray phase analysis [28] of such samples revealed mixtures of three modifi-... 

The X-ray phase analysis of the CMs obtained by these methods (Fig. 8) showed that the modifier coating is pure tin. Moreover, the coherent domain size of tin particles in this case is almost the same as for the materials obtained by thermal vacuum deposition. Besides, it is necessary to... 

Following variant II, after treating by the modifier, the solid phase was separated by filtration and additionally washed off with 0.2 liters of water under vacuum of the water-jet pump. Further, as in variant I, one part of the product was dried at 105°C for two hours (product C), while the other was dried at 20°C until a sample mass became constant (product D). The products were investigated by the powder X-ray phase analysis (PXRD) using nickel-filtered CoKa radiation. 

Nd-Zn-Sb. The results of an X-ray phase analysis of 25 ternary neodymium-zinc-antimony alloys for the Sb-rich region (33.0-100.0 at.% of Sb) are presented in fig. 15 (Sologub and Salamakha, 1999). The alloys were obtained via a powder metallurgical reaction,... 

The researched alloy as spherical particles by a diameter of 0.1, 0.4, 0.6 and 0.8 mm contained, on the data chemical and microrontgenospectral analyses, 92.05 mass% of Ti, 4.52 mass% of A1 and 3.43 mass% of Sn. According to the results of the X-ray phase analysis, the initial alloy is homogeneous and represents a solid solution of aluminum and tin in a-titanium which crystallizes in a... 

TABLE 4. Phase structure of titanic electrolytic powders after corrosion in 5 % a solution HC1 (the X-ray phases analysis)... 

Chemical reactions proceeding in the system under the conditions of IR pyrolysis result in the changes of PAN crystalline structure. X-ray phase analysis (XRPA) has shown that at T>200°C in the course of formation of ordered carbon structures crystalline and amorphous phases of initial PAN disappear, while another amorphous carbon phases appear [12] ... 

Magnesium silicates. Mechanochemical reaction between Mg(OH)2 and Si02 was investigated in [21]. Activation was carried out in a laboratory vibratory mill. According to X-ray phase analysis data, for individually activated Mg(OH)2 no changes in structure and composition are observed, except for the decrease of peak intensities due to... 

The mixtures were activated in a planetary mill for 20 h, then studied by means of modern physicochemical methods (DTA, X-ray phase analysis,... 

CujCOjCOH) with atomic ratio Y Ba Cu = 1 2 3 in a planetary mill for 10 min and heating within the range 675-900°C in 25° steps for 1 h resulted, according to X-ray phase analysis, in the formation of YBa2Cu307, ... 

Iridium-rhodium alloys were prepared in electric arc furnace in argon atmosphere by smelting refined powders of rhodium and iridium of 99.95 mass% purity. The composition of the alloys was controlled by the atomic adsorption analysis using the Perkin-Elmer spectrophotometer with HUS-72 analyzer. X-ray phase analysis indicated that all binary systems had a single-phase FCC-structure characteristic of... 

In the study of the structure, i.e. the ionic composition of the investigated molten electrolyte, the physico-chemical analysis, based on the results of measurements of phase equilibrium, density, surface tension, viscosity, and electric conductivity of melts, combined with X-ray phase analysis and IR, respectively, Raman spectroscopy of quenched melts, is used. In the last two measurements, it may be assumed that the high temperature composition is at least qualitatively conserved after quenching. In the investigation of the structure of the electrolytes, the so-called chemical approach is used. 

The X-ray phase analysis of samples was carried out using a HZG-4C diffractometer (Cu K radiation and a flat monochromator) in the range of 20 angles equal to 1-70°. The unit cell parameter of ceria and modified composites was determined from the position of 311 diffraction peak. 

X-Ray Phase Analysis an analytical technique for identification of mineral phases in rocks, soils, clays, or mineral industrial material based on XRD. 

Precise x-ray phase analysis has confirmed the presence of all the phases observed with electron microscopy. Moreover it is evidence of arise of the second silicide phase close to Ti2Si (S2) except of Ti5Si3 (Si) after plastic deformation as well as after additional annealing (Fig. 6). It is become obvious why [3-phase, which is well-visible with both light and electron, SEM and TEM, microscopies, is not observed with conventional x-rays analysis of the Ti-Si-alloys. The answer is very simple. Comparing Fig. 6 and Fig. 7 it is seen that the reflex referencing to [3-phase is overlapped by one of the S2 reflexes that does it invisible. 

O. 8 and 1.0) were prepared by Co-precipitation method. Characterisation was done by X-ray phase analysis and DRS studies and by measurements of surface area and electrical conductivity. The amount of metallic copper and monovalent copper were estimated by reversible adsorption of CO respectively. Hydrogenation of nitrobenzene to aniline was carried out at 250°C in a fixed bed flow type reactor. Comparison of hydrogenation activity with CO adsorption data show that monovalent copper is more active than metallic copper for the hydrogenation of nitrobenzene. 

X-ray phase analysis of the sample performed at room temperature (RT) ensured a perovskite-type structure of the crystal reflections of other phases... 

The simplified accelerated X-ray spectroscopy method is presented in this work. The X-ray common use diffractometers which are utilized in X-ray phase analysis may be used to that end. The duration of the date recording did not exceed several minutes in our experiments. 

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