JCPDS Research Articles

Cynarine monohydrate from synchrotron powder X-ray diffraction data.

The crystal structure of cynarine monohydrate (systematic name: 1,3-bis{[(E)-3-(3,4-dihydroxyphenyl)prop-2-enoyl]oxy}-4,5-dihydroxycyclohexane-1-carboxylic acid monohydrate), C25H24O12·H2O, has been solved and refined using synchrotron powder X-ray diffraction data, and optimized using density functional techniques. Despite being purchased as anhydrous, cynarine crystallizes as a monohydrate and the crystal structure is characterized by alternating layers of hydrocarbon and hydrogen-bonding interactions parallel to the bc plane. Hydrogen bonds are significant in the crystal structure. The carboxylic acid group forms a strong intermolecular hydrogen bond to a hydroxy group of the quinic acid ring. Most of the hydroxy groups act as donors in O-H...O hydrogen bonding to carbonyl O atoms. One hydroxy group participates in bifurcated hydrogen bonds, one to a hydroxy group on the quinic acid ring and the other, an intramolecular interaction, to another hydroxy group. The powder pattern has been submitted to the International Centre for Diffraction Data (ICDD) for inclusion in the Powder Diffraction File (PDF-4).

ANALYSIS OF LATTICE PARAMETER, ERROR, AND THE BANDGAP ENERGY IN CADMIUM SULFIDE (CdS) SEMICONDUCTOR MATERIAL

Has successfully analyzed the lattice parameter, error, and energy band gap of Cadmium Sulfide (CdS) material. CdS is a semiconductor material. In this study, the CdS used is a material with a cubic crystal structure using database from the International Center for Diffraction Data (ICDD), then the data is calculated using the Cramer-Cohen method. From these data the resulting lattice parameter of a = b = c = 5.823791777 Å with an average error of 0.00034%. The band gap energy calculation of CdS material is 2.477 eV.

THE PARAMETER ANALYSIS OF CUBICAL STRUCTURED CADMIUM TELLURIDE (CdTe) SEMICONDUCTOR MATERIALS

Cadmium telluride (CdTe) semiconductor materials will be used to analyze the energy gap, lattice parameters, and error value of these cubical structured crystal materials. The data that we used to be analyzed is using data from the International Center for Diffraction Data (ICDD) that used the X-ray Diffraction (XRD) method. This research has been successfully analyzing energy gap, lattice parameters, and the error value of Cadmium telluride (CdTe) materials which have a cube-shaped crystal structure. The result of the gap energy analysis of Cadmium telluride (CdTe) with a cubical structure yields a value of 1.43 eV. The lattice parameters of Cadmium telluride (CdTe) with a cubical structure analyzed by the Cramer-Cohen method yields a value of a = b = c = 9.922 Å. The error value of Cadmium telluride (CdTe) with a cubical stcucture yields a value of 6.75 x 10-4 %.

The full plate: benefits of simulated and raw data digital patterns in the Powder Diffraction File

The full plate: benefits of simulated and raw data digital patterns in the Powder Diffraction File

Jupyter Notebooks for Civil Engineering concrete structural design

The importance of software continues to grow for all areas of scientific research, no less for powder diffraction. Knowing how to program a computer is a basic and useful skill for scientists. This paper explains the three approaches for programming languages and why scripting languages are preferred for non-expert programmers. The Python-scripting language is extremely efficient for science and its use by scientists is growing. Python is also one of the easiest languages to learn. The language is introduced, as well as a few of the many add-on packages available that extend its capabilities, for example, for numerical computations, scientific graphics, and graphical user interface programming. Resources for learning Python are also provided. ©2014 International Centre for Diffraction Data. [doi:10.1017/S0885715614000931]

Crystal structure of donepezil hydrochloride form III, C24H29NO3⋅HCl

The crystal structure of donepezil hydrochloride, form III, has been solved with FOX using laboratory powder diffraction data previously submitted to and published in the Powder Diffraction File. Rietveld refinement with GSAS yielded monoclinic lattice parameters of a = 14.3662(9) Å, b = 11.8384(6) Å, c = 13.5572(7) Å, and β = 107.7560(26)° (C24H30ClNO3, Z = 4, space group P21/c). The Rietveld-refined structure was compared to a density functional theory (DFT)-optimized structure, and the structures exhibit excellent agreement. Layers of donepezil molecules parallel to the (101) planes are maintained by columns of chloride anions along the b-axis, where each chloride anion hydrogen bonds to three donepezil molecules each.

English

Fusarium oxysporum is an entomopathogenic fungus, and it has anti-biological activity against larvae of mosquitoes. Aedes mosquitoes are responsible for transmitting different diseases in humans. The use of chemical insecticides against mosquitoes is not eco-friendly option and results in the development of insecticidal resistance in mosquitoes. We investigated a biological control activity against these mosquitoes. In the present study, we cultured a local isolate of F. oxysporum from soil samples collected from Lahore, Pakistan and were initially identified based on its morphology and then confirmed through PCR. A product of 339 bp was amplified from the ITS (Internal Transcribed Spacer) gene of the fungus and sequenced afterwards. The sequence was in clad with Fusarium, which was isolated from a mosquito's body in the phylogenetic analysis. Local F. oxysporum was cultured and silver NPs (nanoparticles) were prepared. UV-Vis analysis depicted a broad peak at 420 nm wavelength and a narrow height at 310 nm. X-ray diffraction patterns of NPs indicated the existence of sharp diffraction peaks at 2θ angles of 32.19°, 45.55° and 64.27° that can be indexed to the (101), (200) and (220) facets of silver, which agree with the values reported for fcc lattice of silver NPs in International Center for Diffraction Data (ICDD). The SEM (scanning electron microscope) micrograph showed well-defined spherical NPs, which were smooth, isotropic, poly-dispersed, and ranging from 10 nm to 200 nm. The Zeta potential (ZP) measurements and poly-disparity index of 0.16 by DLS revealed a low variability of particle size and exhibited good physiochemical stability of biosynthesized AgNPs. In the Fourier-transform infrared spectroscopy (FTIR) spectrum of biosynthesized AgNPs, strong bands were analyzed at 3280 cm-1 and 1635 cm-1. F. oxysporum NPs enhanced the anti-biological activity by killing Aedes larvae 7 h earlier than F. oxysporum without NPs. Biological control using entomopathogenic fungi can be the best alternative of the chemical method to control the mosquito population. © 2021 Friends Science Publishers

Preparation of Hexagonal SrMnO₃ High-Quality Target for Magnetron Sputtering.

In recent years, the optical behavior of complex oxides are being increasingly used in light-harvesting applications. Perovskites are promising candidates for photovoltaic, photocatalytic, and optoelectric applications because of tunable band gaps and other unique properties such as fer-roelectricity To study the optical behavior of ferromagnetic-ferroelectric oxides, SrMnO₃ (SMO₃) targets intended for use in magnetron sputtering were prepared using SrCO₃ (99.99%) and Mn₂O₃ (99.99%) powders by a two-step solid reaction method. Experiments were performed at various temperatures to determine the optimum calcination temperature of the SMO₃ powder (1000 °C) and optimum sintering temperature of the prepared target (1300 °C), in an effort to optimize the preparation process of the target at the laboratory scale and reduce the cost of the target by more than 20-fold. Samples of the ground powder were calcined at 800, 1000, 1200, and 1300 °C for 10 h, and the resultant targets were pressed into 1 -in molds after grinding and subsequently sintered at the same temperatures at which the corresponding powders were calcined, i.e., at 800, 1000, 1200, and 1300 °Cfor 48 h. The microcrystalline state of the powders was observed by scanning electron microscopy. The prepared targets were analyzed by X-ray diffraction, and the results were compared with the powder diffraction file card of hexagonal SMO₃ to determine the optimum calcination temperature and sintering temperature of the powder formulation. Finally, the Vickers hardness values of the targets were measured, and the optimum target preparation process was determined.

Powder Diffraction Data of Aluminum-Rich FCC-Ti1−xAlxN Prepared by CVD

Fcc-Ti1−xAlxN-based coatings obtained by Physical Vapor Deposition (PVD) or Chemical Vapor Deposition (CVD) are widely used as wear-resistant coatings. However, there exists no JCPDF card of fcc-Ti1−xAlxN for the XRD analysis of such coatings based on experimental data. In this work, an aluminum-rich fcc-Ti1−xAlxN powder was prepared and, for the first time, a powder diffraction file of fcc-Ti1−xAlxN was determined experimentally. In the first step, a 10 µm thick Ti1−xAlxN coating was deposited on steel foil and on cemented carbide inserts by CVD. The steel foil was etched and flakes of a free-standing Ti1−xAlxN layer were obtained of which a part consisted of a pure fcc phase. A powder was produced using the major part of the flakes of the free-standing Ti1−xAlxN layer. Following the Ti1−xAlxN coating, a flake of the free-standing layer and the powder were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), selected area electron diffraction and high-resolution transmission electron microscopy (SAED–HRTEM), wavelength dispersive X-ray spectroscopy (WDS) and energy dispersive X-ray spectroscopy (EDS). The powder consisted of 88% fcc-Ti1−xAlxN. The stoichiometric coefficient of fcc-Ti1−xAlxN was measured on a flake containing only the fcc phase. A value of x = 0.87 was obtained. Based on the powder sample, the XRD data of the pure fcc-Ti1−xAlxN phase were measured and the lattice constant of the fcc-Ti1−xAlxN phase in the powder was determined to be a = 0.407168 nm. Finally, a complete dataset comprising relative XRD intensities and lattice parameters for an fcc-Ti0.13Al0.87N phase was provided.

(Invited) Use of Secondary Materials in NMC Co-Precipitation: Effect of Impurities on the Cell Performance

The growing demand for raw materials in lithium-ion batteries increasingly requires the increased use of secondary raw materials in the co-precipitation of NMC battery chemicals. Traditionally, pure raw materials as metal solutions are required for co-precipitation, which is a challenge for battery producers. Removal of impurities is also expensive and challenging step. Aim of this research is to study the impact of impurities present in metal sulfate solutions on the battery cell performance. These metal sulfate solutions were obtained from metal industry’s side-stream and from recycled spent batteries.Metal sulfate solutions with known amount of impurities were used in (Ni0.8Co0.1Mn0.1)OH2 (NMC811) precursor co-precipitation. Commercial pure manganese and nickel sulfates were used as reference samples. Key impurities in the solutions were zinc, iron, calcium, potassium, lithium, and magnesium. Composition of samples was determined using ICP-OES. We also demonstrate actions to control precipitation of impurities during the NCM precursor co-precipitation. Solubilities of impurities were calculated using MEDUSA and HYDRA.Dried hydroxide precursor (sieved <25µm) was mixed with LiOH in molar ratio of Li:(Ni0.8Co0.1Mn0.1:Al) 1.04:0.996. LiOH excess was used to compensate lithium loss during high temperature calcination and ensure homogenous lithiation. The mixture calcined with 2.5°C/min heating ramp and 6 hours holding time at 800 °C under O2 flow. Material was milled and sieved <40µm in the dry room conditions. Residual lithium washed from surface with certain amount of de-ionized water and dried in vacuum oven.Cathode slurry was mixed with Thinky ARE 250 mixer. Slurry composition was 4% of PVDF, 4% carbon and 92% active material and NMP as solvent. Cathode slurry was spread on aluminum foil with 100 µm applicator, then dried at 50 °C for few hours and finally at vacuum oven at 120 °C overnight. Cathode foil was calendered three times before coin cell assembly. The active material loading on the foil was about 12 mg/cm2. Theoretical capacity used to calculate the C-rate was 200 mAh/g. Electrochemical performance was carried out using one electrode pair pouch cell (50 mAh) was prepared with graphite anode, and electrolyte was 1.15M LIPF6 in EC:DMC:EMC (2:4:4) and 1 % of vinylane carbonate. All foils and coin cells were prepared in the dry room. Cells tested between 4.2V-2.8V. 1100 cycles at 1C/1C currents including capacity check every 100 cycles at 0.2C/0.2C currents. Before the capacity check, cell was discharged at 0.2C.The microstructure shown by field emission scanning electron microscope (FESEM) images was obtained using a Zeiss Sigma FESEM operating at 5kV at the Centre for Material Analysis of the University of Oulu. X-ray diffraction (XRD) analysis was done for the calcined NCM811 cathode materials by using Rigaku SmartLab 9 kW with Co-Kα radiation at 40 kV and 135 mA. Diffractograms were collected in the 2θ range (5–120° at 0.01° intervals). Diffraction peaks and crystallite parameters were identified using International Centre for Diffraction Data (PDF-4+ 2020). The specific surface areas, pore sizes and pore volumes of samples were determined from nitrogen adsorption desorption isotherms at the temperature of liquid nitrogen (−196 ◦C) using a Micromeritics ASAP 2020.The tapped density of powders was measured based on the ISO EN 787/11 standard. Residual lithium was measured with an automatic titrator. Particle size distribution (PSD) during the co-precipitation was measured with a Malvern Mastersizer 3000.Based on the results, co-precipitation of impurities to the NMC particles followed the thermodynamic calculations. As expected, iron, zinc, magnesium and calcium co-precipitated in NMC811 to a large extent, but potassium and lithium remain in the mother liquor. The presence of impurities was also confirmed by several characterizations. Impurities did not affect the particle morphology or tap density of NMC811. Surprisingly, the effect of impurities was also minor to the cell performance. During the cycling, these cells provided good cyclability and remain high retention (>80%) after 1100 cycles compared to reference samples.

Crystal Structure of Linagliptin Hemihydrate Hemiethanolate (C25H28N8O2)2(H2O)(C2H5OH) from 3D Electron Diffraction Data, Rietveld Refinement, and Density Functional Theory Optimization

The crystal structure of linagliptin hemihydrate hemiethanolate was solved by direct methods and refined by least-squares on the basis of 3D electron diffraction data. Linagliptin is one of the largest organic structures solved ab initio by electron diffraction. The good quality of the data allows the recognition of subtle symmetry reductions and of fine differences in the configuration of the two independent molecules that make up the structure. The structure was then further refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. The linagliptin hemihydrate hemiethanolate structure is very similar to the known linagliptin water/methanol/ethanol Form I, and crystallizes in space group P21212 (#18) with a = 24.85091(13), b = 21.56916(9), c = 9.74376(4) Å, V = 5222.79(3) Å3, and Z = 4. Although the compounds are similar, they are not the same, so the linagliptin hemihydrate hemiethanolate structure is a novel one. The powder pattern from a Le Bail fit to synchrotron data is included in the Powder Diffraction File as entry 00-066-1626.

A Novel Open-System Method for Synthesizing Muscovite from a Biotite-Rich Coal Tailing

According to the wide application of muscovite in various industries, many studies have focused on its fabrication. However, the process of its synthesis faces long-standing challenges mainly related to the elevated temperature and pressure ambient, together with time and cost-consuming processes. This research work aims at synthesizing muscovite through a straightforward and direct wet thermal oxidation of an ash sample produced from biotite-rich coal tailings. For this purpose, the lab ash powder was mixed with 35% H2O2 at the room temperature of 25 °C while stirring at 480 rpm. Then, the temperature was gradually raised to 80 °C, and the process ran for 180 min. The dried product and the raw lab ash were characterized by the X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) methods. The XRD results indicated that the biotite was efficiently converted to the muscovite as the number of relevant peaks was significantly increased in the synthesized product’s pattern. The SEM and FTIR results showed some structural changes, from pseudo-hexagonal in the starting material to amorphous pseudo-crystals in the synthetic product, as well as the growth of the product’s crystals. The crystallographic study and lattice parameter calculations revealed that the starting material and product peaks matched to International Center for Diffraction Data (ICDD reference patterns of 01-080-1110 and 01-082-2450 for the biotite and the muscovite, respectively. Moreover, the calculation of the mean crystallite size of the starting material and treated samples were obtained as 55 nm and 87 nm, respectively. Finally, according to the characterization properties of synthesized muscovite, the presented method was introduced as an effective technique. Therefore, we highly suggest it for further consideration and its development in future investigations.

An environment friendly synthesis and characterization of Zinc Oxide nanoparticles using Mentha viridis leaf extract

Zinc Oxide Nanoparticles (ZnO Nps) are one of the most predominant inorganic nanoparticles, which have diverse applications in the field of cosmetic, coating, medicine and electronic sensors. Morphology and particle size of nanoparticles mainly control its advantages and drawbacks in applications. In this study, an environment friendly and economic synthesis of ZnO Nps was carried out using Mentha viridis leaf extract as reducing and stabilizing agent to investigate the morphology, particle size and other properties of the synthesized ZnO nanoparticles. A series of characterization methods: ultraviolet-visible (UV-Vis) spectroscopy, x-ray diffraction analysis, field emission scanning electron microscopy (FESEM) and energy dispersive x-ray analysis (EDX) were used to confirm the characteristics of the synthesized nanoparticles. It was evident from the XRD analysis that ZnO Nps possess a polycrystalline hexagonal structure (as per the International Centre for Diffraction Data (ICDD) number #98-002-9272) with an average crystallite size of 32.3 nm. The spectra showing peaks in the EDX data indicated the presence of Zn (50.35 %) and O (49.65 %) in higher percentage and FE-SEM analysis revealed the morphology and Average Length and diameter of the nanorods are 156 nm and 48 nm respectively of the synthesized ZnO Nps. The analysis of the UV visible absorbance spectrum revealed the absorbance band peak at 372nm and confirmed the presence of ZnO Nps. From all these analyses, it is evident that Mentha viridis leaf extract can act as a potential reducing agent in the green synthesize ZnO Nps.

Remarkable bactericidal traits of a metal-ceramic composite coating elated by hierarchically structured surface.

SummaryA ceramic-based coating with a hierarchical surface structure was synthesized via solid-state reaction enabled by a double cathode glow discharge technique. This innovative coating comprises two distinct layers, specifically an outer layer with a well-aligned micro-pillar array and a dense inner layer. Both are composed of a face-centered cubic Cu(Co,Ni,Fe) solid solution phase together with a spinel-type Fe(Al,Cr)2O4 oxide. This coating exhibits superhydrophobicity and, yet, a very strong adhesion to water, i.e., the so-called “rose petal effect”. This coating also exhibits highly efficient antibacterial ability against both Staphylococcus aureus and Escherichia coli bacteria under both dark and visible light conditions. The excellent antibacterial property originates from the synergistic effects through the release of Cu ions coupled with photothermal activity upon light activation.

Orthophosphate Interactions with Destabilized PbO2 Scales.

This research presents two case studies in which a change in the disinfectant from free chlorine to chloramine caused an increase in lead corrosion. In both systems, the predominantly tetravalent lead (PbO2) scales destabilized as a result of disinfectant change. Orthophosphate corrosion control was used in both systems, and the effect of this treatment chemical on the destabilized PbO2 scales was examined. The absence of chemical reactivity between PbO2 and phosphorus is well known, and this research confirms that phosphorus does not interact with the legacy PbO2 scales. Instead, phosphorus and calcium were found to permeate through the destabilized PbO2 material and react with divalent lead [Pb(II)] at the surface of a basal litharge (PbO) layer. This reaction precipitated a crystalline lead phosphate in both systems, which could not be specifically identified by any known powder diffraction files. Further analysis suggested that the compound formed was not the typically modeled hydroxypyromorphite but rather a calcium-substituted hydroxypyromorphite. During scale formation, calcium is frequently bound to the Pb(II) phosphate crystal lattice structure, causing measurable crystal lattice distortion in powder X-ray diffraction patterns. The results of this study illustrate the longevity of legacy scales and how disequilibrium compounds persist long after treatment changes have been made.

Structural Characterization of Co-Crystals of Chlordiazepoxide with p-Aminobenzoic Acid and Lorazepam with Nicotinamide by DSC, X-Ray Diffraction, FTIR and Raman Spectroscopy.

The low water solubility of benzodiazepines seriously affects their bioavailability and, in consequence, their biological activity. Since co-crystallization has been found to be a promising way to modify undesirable properties in active pharmaceutical ingredients, the objective of this study was to prepare co-crystals of two benzodiazepines, chlordiazepoxide and lorazepam. Using different co-crystallization procedures, slurry evaporation and liquid-assisted grinding, co-crystals of chlordiazepoxide with p-aminobenzoic acid and lorazepam with nicotinamide were prepared for the first time. Confirmation that co-crystals were obtained was achieved through a comparison of the data acquired for both co-crystals using differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Fourier-transform infrared (FTIR) and Raman spectroscopy, with comparisons acquired for the physical mixtures of both benzodiazepines and coformers. The compatibility of PXRD patterns of both benzodiazepines co-crystals with those contained in the base Powder Diffraction File (PDF-4+) suggests that new crystal structures were indeed created under the co-crystallization procedure. Single-crystal X-ray diffraction revealed that a chlordiazepoxide co-crystal with p-aminobenzoic acid and a lorazepam co-crystal with nicotinamide crystallized in the monoclinic P21/n and P21/c space group, respectively, with one molecule of benzodiazepine and one of coformer in the asymmetric unit. FTIR and Raman spectroscopy corroborated that benzodiazepine and coformer are linked by a hydrogen bond without proton exchange. Furthermore, a DSC study revealed that single endothermic DSC peaks assigned to the melting of co-crystals differ slightly depending on the co-crystallization procedures and solvent used, as well as differing from those of starting components.

Effects of microwaves on the dehydration characteristics of santite

In this paper, by using the microwave irradiation, the dehydration curves of santite (KB5O8·4H2O) were obtained and modeled. By using a different mathematical model, the kinetic parameters of the dehydration process were determined. The dehydration of santite was completed at 180, 105 and 60 min for 360, 600 and 800 W, respectively. The characterization techniques of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy were applied to the obtained santite mineral and dehydrated santite mineral. From the obtained XRD analysis, santite, its powder diffraction file number is 01-072-1688 transformed into an amorphous phase after the microwave dehydration process. From the FT-IR and Raman analyses, it can be said that partial dehydration was achieved due to the disappearance of structural H2O bands but remaining some hydroxyl bands. For the modeling results, Verma model best fits the experimental data obtained from the dehydration and the dehydration activation energy was calculated as 11.92 kW × g–1.

Crystal chemistry, X-ray diffraction reference patterns, and bandgap studies for (BaxSr1–x)2CoWO6 (x = 0.1, 0.2, 0.3, 0.5, 0.7, and 0.9)

X-ray reference powder patterns and structures have been determined for a series of cobalt- and tungsten-containing cubic alkaline-earth perovskites, (BaxSr1–x)2CoWO6 (x = 0.1, 0.2, 0.3, 0.5, 0.7, and 0.9). The structure of the end members of the series, Sr2CoWO6 and Ba2CoWO6, were tetragonal and cubic, respectively, agreeing with the literature data. From Rietveld refinements, it was found that when x = 0.1 and 0.2, the structure was tetragonal I4/m (a = 5.60481(6) and 5.62305(11) Å and c = 7.97989(12) and 7.9847(2) Å, respectively; Z = 2). When x &gt; 0.2, the structure was cubic (Fm$\bar{3}$m, No. 225; Z = 4) (from x = 0.3 to 0.9, a increases from 7.98399(13) to 8.08871(10) Å). This tetragonal series of compounds exhibit the characteristics of a distorted double-perovskite structure. The bond valence sum values for the alkaline-earth (Ba, Sr) sites in all (BaxSr1−x)2CoWO6 members are greater than the ideal value of 2.0, indicating over-bonding situation, whereas for the W sites, as x increases, a change from under-bonding to slightly over-bonding situation was observed. Density functional theory calculations revealed that while Sr2CoWO6 is a semiconductor, Ba2CoWO6 and SrBaCoWO6 are half-metals. Powder X-ray diffraction patterns of this series of compounds (BaxSr1−x)2CoWO6, with x = 0.1, 0.2, 0.3, 0.5, 0.7, and 0.9, have been submitted to be included in the Powder Diffraction File.

The effects of substrate on enhancement of UV emission of ZnO nanorods

We have synthesized ZnO nanorods by hydrothermal at 95 °C for two hours on different substrates i.e. glass, ZnO, and ITO. Morphologically, the average diameter of ZnO nanorods on glass, ZnO, ITO are 117.6 µm, 133 µm, 98.4 µm, respectively. According to the international center for diffraction data (ICDD) number #01-079-0207, the ZnO nanorods on all substrates possess a polycrystalline wurtzite structure. By full width at half maximum (FWHM) of ZnO NRs in (002) plane, we have determined crystallite size and micro-strain using Scherer’s equation and Stokes-Wilson equation, respectively. The crystallite size and micro-strain of ZnO NRs vary with different kind of substrates. Optically, ZnO nanorods on a glass substrate have the strongest excitonic-related ultraviolet (UV) emission. Further observation, we have determined the UV/GB ratio to confirm the crystalline quality of ZnO NRs on glass, ZnO, and ITO substrates. These UV/GB ratios are 101.35, 68.14, and 22.74. It is indicating the ZnO NRs on glass has a better crystalline quality which indicates fewer native defects concentration compared to the others.

Исследование особенностей фазообразования при совместном алюминотермическом восстановлении ZrO2, Ta2O5, Nb2O5

In this paper, we consider the advantage of using the metallothermic method for producing alloys, in contrast to traditional methods. Using the HSC Chemistry 6.1 software package, thermodynamic modeling was performed. The possibility of obtaining intermetallic compounds by the joint aluminothermic reduction of Zr, Ta, Nb oxides is shown. The alloy was obtained by aluminothermic reduction of aluminum, zirconium, tantalum and niobium oxides in a resistance furnace, followed by grinding and powder size 40-100 microns. An experimental study of the sequence of phase formation and the boundaries of their existence was investigated using differential thermal analysis (DTA). The experiment was carried out on a STA 449 F3 Jupiter (NETZSCH) synchronous thermal analysis instrument in an argon flow GOST 10157-79 (the volume fraction of argon is at least 99.993%), the flow rate of the gas used was 30 ml/min. X-ray phase analysis (XRD) of the products (after DTA) was carried out on an XRD 7000 diffractometer (Shimadzu). By the relative intensity of the lines of the various phases, their quantitative ratio was estimated. The diffraction patterns were decoded using literature data, as well as the JCPDS (International Center For Diffraction Data) and ASTM (American Society for Testing and Materials) databases. According to the obtained XRD data, in the sample at temperatures of 954.5 and 1309.1 ºС, respectively, the formation of a solid solution (Zr, Nb, Ta)Al2 occurs, which is isostructural to the intermetallic Al3Zr. In both cases, the concomitant ZrAl2 intermetallic compound is also formed. The performed study can serve as a scientific basis for the development of promising metallothermal technologies for the production of rare metal alloys.