In this study, we have investigated structure and impurities of six different salts which have a great importance in our everyday life, namely source salt, Himalayan salt, rock salt, sea salt, lake salt and reduced sodium salt (minsalt) by means of different analytical methods, namely X-ray powder diffraction, scanning electron microscope-energy dispersive X-ray spectroscopy, inductive coupling plasma optic emission spectroscopy, X-ray fluorescence spectrometer and the Fourier transform infrared spectroscopy. With the light of obtained results, suitability and performance of the different analytical methods were discussed in some details.
In the paper the crystal structure of single crystal CMSX-4 blade casts, applied in high pressure turbine of aircraft engines was analyzed. The longitudinal section of blade, cast at withdrawal rate of 3 mm/min was used as a sample. During the conducted research, following X-ray diffraction methods were applied: EFG Ω-scan, Auleytner X-ray topography and analysis of diffraction reflex profile ("rocking curve"). The authors determined crystal orientation in entire blade casts on the basis of set criterion concerning values of angle α - deviation of [001] direction from the direction of cast withdrawal. Conclusions concerning the crystal structure quality of the blade were drawn based on results from three different research methods. Local changes in crystal orientation on the surface of blade cast, also areas with significant structure defect degree and the presence of internal stresses were characterized.
The aim of the present work was to study the isothermal compression and isobaric thermal expansion behaviour of ball-milled NiFe (81 wt.% of Ni) and NiFeMo (79 wt.% of Ni, 16 wt.% of Fe) alloy and follow its phase evolution when exposed to high pressure and temperature. In-situ pressure-temperature energy dispersive X-ray (EDXRD) diffraction experiments were performed at the MAX80 instrument (beamline F2.1). The compressibility of NiFe alloy at 400 °C was evaluated for pressure values of up to 3.5 GPa. The EDXRD spectra revealed the presence of cubic FeNi_{3} phase as determined from the shift of (111), (200) and (220) reflection lines in corresponding EDXRD spectra.
ZnO thin films were deposited on microscope glass substrates by ultrasonic spray pyrolysis technique. The effects of annealing under various temperatures on the optical and structural properties of ZnO thin films were analyzed. The as-deposited and annealed ZnO thin films were investigated by UV/VIS spectrophotometer and X-ray diffractometer. Some of the optical properties of the films such as transmittance, absorbance and band gap energy were investigated by UV/VIS spectrophotometer. The crystallinity levels of the films were investigated, the structural parameters such as diffraction angle, full-width at half maximum, lattice parameters, grain size and dislocation density were calculated and structural properties were analyzed. X-ray diffraction patterns indicated that the ZnO films had a polycrystalline hexagonal wurtzite structure.
The paper deals with the investigations of structural properties of Zn_{1-x}Mn_xTe films, which were fabricated under various deposition conditions using the thermal evaporation method in a closed volume. The surface morphology of the samples was studied, the phase analysis of their structures was performed, the elemental analysis of the films and the crystal lattice constant were investigated. The texture perfection of the films before and after copper ion implantation was evaluated.
Cd_{1-x}Zn_{x}Se films with different zinc content were deposited by electron beam evaporation technique onto glass substrates for the application of solid-state photovoltaic devices. The structural, surface morphological and optical properties of Cd_{1-x}Zn_{x}Se films have been studied in the present work. The host material, Cd_{1-x}Zn_{x}Se, has been prepared by the physical vapor deposition method of electron beam evaporation technique under the pressure of 1 × 10^{-5} mbar. The X-ray diffractogram indicates that these alloy films are polycrystalline in nature, of hexagonal structure with strong preferential orientation of the crystallites along (002) direction. Linear variation of lattice constant with composition (x) is observed. Surface roughness measured by atomic force microscopy is used to estimate the interface roughness. The optical properties show that the band gap (E_{g}) values vary from 2.08 to 2.64 eV as zinc content varies from 0.2 to 0.8. The surface morphological studies show the very small, fine and hardly distinguishable grains smeared all over the surface. The material properties would be altered and excellently controlled by adiusting the system composition x.
Here we present the results of pilot polycrystalline study of PrNi_4Si. The X-ray study did not confirm the expected CaCu_5-type structure. Instead of this, the orthorhombic structure with the space group Cmmm was found. The zero-field specific heat was measured in the temperature range 2-300 K. The data were analyzed using the sum of the phonon, electronic, and magnetic contributions to specific heat, respectively. The magnetic part of the specific heat can be well described using the Schottky formula for the 9 crystal-field singlet levels of the pz3 H4 ground-state multiplet of the Pr^{3+} ion.
Thin layers X-ray diffraction study technique utilizing single-crystal X-ray diffractometer equipped with microfocus X-ray tube is described. It is shown that the layers of the tetra-fluorinated cobalt phthalocyanine (CoPcF₄), deposited by thermal evaporation in vacuum on a polished surface of the substrate (glass, quartz), have a highly oriented polycrystalline structure. All the crystallites have the (00l) plane oriented along the surface of the substrate. CoPcF₄ X-ray diffraction pattern indexing was conducted and unit cell parameters were determined. It is shown that crystal phase of both polycrystalline powder and thin layers of CoPcF₄ are isostructural to that of α -CoPc.
Based on previously discovered forbidden values of the c/a ratio, we studied anomalies in the temperature evolution of the lattice parameters (a, c) of several hexagonal RTAl compounds at high temperatures (above room temperature). The compound ErNi_{0.45}Cu_{0.55}Al, that seemed to be impossible to be prepared in single-phase form, reaches the single-phase state at temperatures above 493 K (220°C). On the other hand, the compound TbNi_{0.7}Cu_{0.3}Al - that was expected to undergo a first-order structural phase transition at high temperatures - exhibits a second-order type transition when approaching the critical values of the c/a ratio. These results are in agreement with idea of a forbidden range of c/a values in these compounds.
The law of growth of nitrided layers produced by gaseous nitriding of 31CrMoV9 alloy steel at different process parameters is described. 31CrMoV9 steel specimens were subjected to nitriding process in ammonia gas at three different temperatures: 510, 550 and 590°C, and for each temperature four different nitriding times were used. This way twelve specimens were produced. Nitrided specimens were investigated with optical microscopy, electron probe micro-analysis and x-ray diffraction. The nitrogen depth concentration profiles, deduced from electron probe micro-analysis, in conjunction with results of optical microscopy, were used to determine the thickness of the nitrided layers, i.e. the diffusion depth of nitrogen. From the dependence of the nitrided layer thickness on process parameters (temperature and time) it was possible to deduce the law that governs the growth of the nitrided layer for 31CrMoV9 alloy steel. Through this law, then, it is possible to predetermine the layer thickness for every real process parameter in nitriding of 31CrMoV9 steel, which is very important for technological applications.
This work deals with the study of the phase and crystal structure behaviour of new micro- and nanocrystalline ferrites Dy_{1-x}R_xFeO₃ obtained by solid state reactions (R = La, Pr) and sol-gel citrate (R = Nd, Sm, Gd) techniques. It was established that all synthesized samples adopt orthorhombic perovskite structure isotypic with GdFeO₃. Unit cell dimensions and atomic coordinates of the mixed rare earth ferrites derived by full profile Rietveld refinement technique agree well with the data of the "pure" DyFeO₃ and RFeO₃ compounds, thus proving formation of continuous solid solutions Dy_{1-x}R_xFeO₃ in the DyFeO₃-RFeO₃ systems (R = La, Pr, Nd, Sm, Gd). Peculiarity of the Dy_{1-x}La_xFeO₃ series is the lattice parameters crossover and formation of dimensionally tetragonal structure at x ≈0.97.
An alignment study of multi-wall N-doped carbon nanotubes prepared by a template pyrolytic carbon deposition method inside channels of an alumina membrane has been performed using high-energy X-ray diffraction on the ID15B beamline at the European Synchrotron Radiation Facility (ESRF, Grenoble). The two-dimensional diffraction pattern of the deposited carbon nanotubes, recorded directly, within the alumina membrane, using an image plate detector, exhibits two non-continuous arcs corresponding to the 002 graphitic reflection. The following values of the angle between the axis of the carbon nanotubes lying along the membrane channels and the incident beam were taken for five positions: 0°, 30°, 45°, 60° and 90°. The anisotropic scattering distribution of the two-dimensional patterns indicates an orientational alignment of the nanotubes. The one-dimensional intensity patterns obtained by scanning around the circumference of the (0 0 2) ring have allowed an estimation of the angular distribution of the nanotubes axes.
The atomic structure of as-prepared Fe_{61}Co_{(14-x)}Zr_{5}W_{x}B_{20} (x=1, 2 and 4) ribbon samples and their thermal stability were investigated by in-situ high-energy X-ray diffraction experiments. It was observed that higher W concentration causes the tiny shift of the main peak of the reduced atomic pair distribution function to higher values of interatomic distances and increases the coefficient of volume thermal expansion. The crystallization process occurs in two steps and is qualitatively the same for all studied specimens. Firstly the Fe_{23}B_{6} phase is created and later is transformed to other types of borides together with the creation of a Fe-based phase.
Nuclear and magnetic properties of the ScFe_{4}Al_{8} single crystal were found to exhibit unparalleled complexity of nuclear and magnetic structures. Our previous neutron measurements revealed presence of two modulation vectors, both along [ε, ε, 0], however with different critical temperatures. Recent experiments forced us to revise our knowledge of the structural ordering in the sample. So far, the crystal structure of this alloy, being of ThMn_{12}-type, has never been questioned.
Reducibility is a parameter which describes the ability of oxygen, combined with iron, to be removed from iron ore sinters by a reducing gas used in a blast furnace, and is often characterized by a Fe²⁺ content in a sinter. In sinters, iron at Fe²⁺ valence can occur in various types of minerals, which differ in values of reducibility. The set of sinters with the reducibility from 0.63%/min to 1.49%/min, prepared in the different laboratory conditions, were examined in terms of their mineral composition. The quantitative dependences between the fractions of the individual mineral constituents of the sinters and the values of reducibility were sought. The increase of the reducibility was correlated with a decrease of the content of magnetite and a rise of the fraction of hematite.
Short period type-II 10 ML InAs/10 ML GaSb superlattices epilayers (λ_{cut-off}=5.4 μm) have been grown on near lattice matched GaSb (001) substrate and on lattice mismatched GaAs (001) substrate, by molecular beam epitaxy system. In the case of growing on GaAs substrate, GaSb buffer layer was grown in order to reduce the lattice mismatch of 7.5% between GaAs substrate and InAs/GaSb superlattices. X-ray diffraction characterization shows a good crystalline quality for both samples, with a full width at half maximum of 190 arcsec and 156 arcsec for the zeroth-order peak of the superlattice grown on GaAs and on GaSb substrate, respectively. The Nomarski microscopy revealed a shiny surface for both samples with a root main square of surface roughness of 9 nm and 11 nm on the case of growing on GaSb and GaAs substrate, respectively.
The influence of boron contents on the glass forming abilities and magnetic properties of melt-spun ribbon samples produced from Pr₉Fe_{50+x}Co₁₃Zr₁Nb₄B_{23-x} (x=0, 2, 5, 8) alloys, were investigated. For all compositions, the rapidly solidified samples were fully amorphous, which was confirmed by X-ray diffractometry and the Mössbauer spectroscopy. Differential scanning calorimetry and differential thermal analysis studies revealed good glass forming abilities for all investigated specimens and allowed to determine thermal stability parameters of the amorphous phase. For all alloy ribbons, very large supercooled liquid region before crystallization ΔT_x reaching 100 K was measured. The Kissinger plots were constructed to determine the activation energies for crystallization. Annealing of specimens at temperatures ranging from 923 K to 1033 K for 5 min resulted in significant change of the phase constitution. The X-ray diffractometry studies have shown presence of hard magnetic Pr₂(Fe,Co)₁₄B and paramagnetic Pr_{1+x}Fe₄B₄ phases. Furthermore, with the increase of B contents in the alloy composition crystallization of α-Fe phase occurs at wider range of the annealing temperature. Anomaly of both thermal and magnetic properties was observed for the Pr₉Fe₅₂Co₁₃Zr₁Nb₄B₂₁ alloy ribbons.
Besides the crystal preparation, the first and crucial step in the process of protein structure determination is proper processing of the collected diffraction images, as they provide the experimental observations used throughout the entire process of structure solution and refinement. In the last two decades several computer programs have been developed. Among the most used and popular are: HKL2000, MOSFLM, d*TREK and XDS package. To find out the advantages and disadvantages of the data processing programs, several very different data sets, including diffraction data from DNA/RNA and protein crystals were tested. It has been found that all the major programs for processing and analysis of diffraction data give excellent and comparable results with good quality, medium resolution data sets, but their treatment of very high resolution or imperfect data differs in terms of indexing, spot integration, scaling and the treatment of errors. If the diffraction data are of good quality and the problem is relatively straightforward, the automated approach to data processing may be most appropriate. On the other hand, if one is trying to squeeze out as much information from the experimental data as possible, then only expert manual processing can be successful, regardless of the data quality.
In the present paper the phase transformations occurring in hot worked and heat-treated Ni-rich NiTi shape memory alloy were studied using X-ray diffraction, differential scanning calorimetry and bend and free recovery measurements. Based on conducted measurements it can be seen that in the studied alloy two-step B2 ↔ R ↔ B19' phase transitions occurred. Due to the fact that during heating the phase transition B2 → R and R → B19' occurs in a very narrow temperature range and differential scanning calorimetry peaks overlap additional X-ray diffraction measurements were performed. Obtained characteristic temperatures from applied different experimental methods are in good agreement. The optimum heat-treatment was selected to obtain rods with a shape recovery temperature A_{f} below 37°C to prepare prototypes of medical implants activated by patients body heat.
X-ray diffraction, scanning electron microscopy and hardness measurements were applied as experimental methods to investigate the structure and properties of the crystalline-amorphous Al-based composites prepared by mechanical alloying and subsequent high pressure high temperature compaction of the powders. It was possible to obtain bulk, fully dense crystalline-amorphous composites and the applied compaction technique allowed preservation of amorphous structure in the composite. Addition of amorphous Al_{60}Nb_{40} phase to AA6061 alloy resulted in significant increase of hardness of the composite (120 HV), comparing to pure Al alloy compacted at the same conditions (75 HV).
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