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High-entropy alloys (HEAs) and medium-entropy alloys (MEAs) represent an intensively studied group of metallic materials. Due to their unique properties such as their potential to be very stable, wear-resistant, and hard, in addition to the possibility of tailoring some of their properties, HEAs and MEAs also become a subject of study as biomaterials. Commonly used metal biomaterials for implants still have many drawbacks, such as low wear and corrosion resistance or lack of antibacterial properties, which can even lead to implant loss. To improve the surface properties of common implants, MEAs thin films based on Ti-Zr-Nb were prepared by magnetron sputtering, and their structure was determined using transmission electron microscopy. The films were deposited on carbon and silicon substrates and different degrees of crystallinity were revealed depending on the film thickness and the type of the substrate. It was revealed that the crystalline region has tetragonal body-centered structure, with the crystal lattice elongated in the direction of growth. [ABSTRACT FROM AUTHOR]

This research focuses on the structural and spectral insights of unadulterated and doped L-alanine crystals. Barium chloride is considered as the dopant in this study. The various crystals under study are synthesized using slow evaporation technique. The harvested crystals underwent comprehensive characterization through various analyses. The paper primarily delves into the structural and spectral characteristics of the developed crystals. The crystal structure was established utilizing X-ray diffraction (XRD) method which provides details of the spatial arrangement of atoms within the crystal lattice. Additionally, Fourier Transform Infrared (FTIR) Spectroscopy played a crucial role in identifying functional units, internal molecular structures, and the nature of chemical bonds present in the compound. The combination of these techniques contributes to a comprehensive under-standing of the physical and chemical properties of the Barium chloride-doped L-alanine crystals. This research offers valuable insights into crystal growth processes, doping effects, and the fundamental characteristics of the synthesized material. [ABSTRACT FROM AUTHOR]

In this work we propose new structure-preserving multiple time stepping methods for numerical simulation of charge transfer by intrinsic localized modes in nonlinear crystal lattice models. We consider, without loss of generality, one-dimensional crystal lattice models described by classical Hamiltonian dynamics, whereas charge (electron or hole) is modeled as a quantum particle within the tight-binding approximation. Proposed multiple time stepping schemes are based on symplecticity-preserving symmetric splitting methods recently developed by the authors. Originally developed explicit splitting methods do not exactly conserve total charge probability, thus, to improve charge probability conservation and to better resolve high frequency oscillations of the charge in numerical simulations with large time steps we incorporate multiple time stepping approach when solving split charge equations. Improved numerical results with multiple time stepping methods of charge transfer by mobile discrete breathers are demonstrated in a crystal lattice model example. [ABSTRACT FROM AUTHOR]

At present, experimental studies often do not coincide, and sometimes contradict the mathematical models used to evaluate the physical process during the experiment. Sometimes during the experiment, it is possible to establish new data. Thus, the discovery of monatomic two-dimensional materials not only established the existence of such materials, but also refined the theory of the crystal structure of materials by O. Bravais, which was a "dogma" for almost two centuries. Mathematical models contribute to the development of scientific thought and experimental research; however, the "priority" of research should still be the physical representation of the mechanism of the process. At the same time, the model of the physical process should be applicable not only in this particular study, but also in related areas of research, which will make it possible to establish a single mechanism existing in nature. To do this, it is necessary to analyze between the "separate" concepts and equations existing in science in order to find common patterns. In this paper, it is proposed to establish the relationship between the equation that determines the Poisson's ratio ν and the structure of the crystal lattice in the form of the size parameter of the unit crystal cell of the crystal - a. We will establish this relationship for the elementary cell of iron, which, according to the theory of O. Brave, has a body-centered cubic crystal lattice. [ABSTRACT FROM AUTHOR]

Research work consists in studying methods for obtaining highly effective and high-quality sorbents as a result of changing the chemical composition, physico-chemical properties of the mineral by modifying the clinoptilolite mineral by various chemical methods. Study of the mechanisms of formation of two types of strong Bronsted and three types of Lewis acid sites on the surface of clinoptilolite simultaneously with the process of dehydration as a result of acid modification of clinoptilolite. The mechanisms of the stages of dealumination occurring in the crystal lattice of the mineral clinoptilolite are presented, the main structural changes occurring in the process are shown. The energy effect of the clinoptilolite lattice on the separation process shows that the L1 center formed at the first stage of separation corresponds to the L center of aluminum oxide, and the electron-donating ability of the aluminum cation located in the coordination sphere to the second level is much higher than that of the Si +4 cation, due to to this mechanism, the L-centers (L1 and L2) will have to wait for some time until it is generated. The presence of formed L centers indicates that the probability of formation of L centers with the L3 structure is very low. there may be fourth and fifth centers in the system, but the probability of the formation of a fifth type Lewis center is high, and the energy of its formation will have a significantly negative value compared to the fourth type. An increase in the concentration of hydrochloric acid from 3 N to 6 N during the modification of clinoptilolite leads to a significant increase in dealumination, i.e. from 20 to 50%. However, as the acid concentration increases, the crystal lattices of the dealuminated clinoptilolite are sharply distorted. The purpose of this work is to study the mechanisms of the stages of the dealumination process occurring in the crystal lattice of the clinoptilolite mineral and to determine the main structural changes that occur in this process. [ABSTRACT FROM AUTHOR]

Tin dioxide is a semiconductor with n-type as a crystal structure of rutile. There are few studies on the influence of Mn3+ ions on structural and optical properties. The current paper shows the influence of manganese doping on the structural and optical properties of Sn1-xMnxO2 nanoparticles at (0, 5, 10, 15, 20, 25) % molar doping ratios prepared by the sol-gel method. At 200°C, the dried powders were performed from XRD data of all samples. The shift of the peaks in the XRD patterns towards the higher angles indicates that the manganese ions have been excellentlydoped into the crystal lattice of SnO2 with sequentialincreases in dopant levels. The crystallite size was determined based on the equation of Scherer as well as by FE-SEM it was confirmed that the Tin dioxide nanoparticles are within the nanoscale. As for the effect of doping on the the energy gap, the increase in doping rates led to a clear decrease in the optical energy gap. The reason for this decrease is due to the fact that doping with mangan ese led to an increase in the density of local levels caused by atoms of the doping material within the energy gap. [ABSTRACT FROM AUTHOR]

The photocatalyst system in degrading methylene blue dye and antibiotic ciprofloxacin while simultaneously producing hydrogen was carried out to observe the effect of different Fe concentrations in TiO2 nanoparticles and pH value of the solution. The process of degradation and production of hydrogen simultaneously took place in an acrylic reactor equipped with a Philips 250-Watt lamp. Nanocomposites were synthesized by sonophotodeposition method with Fe(NO3)3 solution. The XRD results showed that the Fe3+ dopant successfully entered the crystal lattice of TiO2 nanoparticles. The results of characterization with UV-Vis DRS showed that the energy gap in Fe-TiO2 nanocomposites was lower than pure TiO2 and could redshifted the absorbance at higher wavelength into visible region. The FTIR results show that the addition of Fe dopant can give higher peak values in the O-H bond. The photocatalysis process in alkaline solution with 1.5% Fe-TiO2 showed the best degradation conversion for methylene blue and ciprofloxacin of 98.5% and 94% respectively. Accordingly, by adding the dopant Fe with concentration of 1.5%wt on the semiconductor TiO2, compared with the bare nanocomposite TiO2 it was able to degrade 75% and 38.46% of methylene blue and ciprofloxacin. In addition, nanocomposite with the best photoactivity could also produce 0.16 µmol, 0.10 µm, and 0.07 µmol of hydrogen for pH 5, 7, and 10 respectively. [ABSTRACT FROM AUTHOR]

A possible technique for giving different materials new properties is impurity doping. Since the 18th century, rare-earth ions have been thoroughly investigated as active dopants in inorganic crystal lattices because of their distinctive optical, magnetic, and electrical capabilities. Rare-earth doping can change doped nanomaterials' size, shape, and crystallographic phase, producing tunable optical responses and improved mechanical and electronic functionalities. Additionally, rare-earth doping can significantly enhance energy conversion and harvesting via tunable and scalable control over doped nanomaterials' final electrical and catalytic performance. A comprehensive repertoire of functional nanomaterials for real-world applications must first be developed, which requires a greater understanding of the crucial role played by rare-earth doping. Different rare earth-doped nanomaterials have been extensively studied for their applications in NIR Bioimaging, photocatalytic activity, bone tissue engineering and implantology, ceramics and composites, micro/nano-electronics, and many more. From the extensive literature survey, it was thought noteworthy to collect and report some of the very recent(period of 2020-2022) synthesized rare-earth doped nanomaterials and their applications in a concise manner in this short review paper. [ABSTRACT FROM AUTHOR]

Non-linear optical (NLO) crystals have vital status in applications in telecommunications, THz imaging and spectroscopy, laser technology, optical communication, and optical storage technologies. The present review article is an attempt to focus on the lithium sulfate monohydrate (LSMH) family of single crystals, having a wide spectrum of applications in NLO assistant devices. The different methods of growth of bulk single crystals of these materials have been reviewed. Non-linear optical studies presented by several researchers are discussed, and it is determined that the addition of a dopant in the crystal lattice of LSMH increases the efficacy of the grown single crystals. Also, this article compared the optical, thermal, and mechanical properties of pure and doped LSMH single crystal and concluded it to be a strong candidate for photonic devices. [ABSTRACT FROM AUTHOR]

Two-dimensional layered materials (MoS2 and WS2) are well-known semiconductors and possess interesting physical properties. The nanostructures of these materials with active edge sites exhibit excellent electrocatalytic activity in acidic and alkaline conditions. Transition metal doping is one great research strategy that made the advancement of electrocatalytic behavior layered semiconductors. Here, the investigations on the electrochemical activity towards HER and supercapacitor studies of Ru doped WS2 nanosheets are presented. XRD analysis reveals that the Ru doped WS2 nanosheets exhibit a 2H-hexagonal crystal structure with evidence Ru was successfully incorporated in the WS2 crystal lattice. It is found that the HER overpotential of the catalyst is decreased with increasing Ru content and reaches the value 103 mV (at 10mA/cm2) for 12 at% of Ru from 186 mV of undoped WS2. Further, the electrochemical double layer capacitance of WS2 is increased with Ru content and the best catalyst of 12 at% of Ru possesses 33.04 mF/cm2 specific capacitance. Clearly, Ru doping has a beneficial effect on the electrocatalytic activity of WS2 nanosheets. [ABSTRACT FROM AUTHOR]

In this work, the effect of adding 0.2% and 0.5% silver on the structure and phase composition of 316L corrosion-resistant steel has been studied. The smelting of modified steel was carried out in vacuum electric arc furnaces. The optimal mode of homogenization annealing was carried out and revealed, which amounted to 1050°C for 9 hours. To study the structure, sections of the alloys were obtained after smelting and after annealing. The structure and phase composition of steels have been studied. Annealing leads to the formation of an austenitic structure, its leveling, and the formation of equiaxed grains ∼50 µm in size. It is shown that the addition of a small amount of silver does not affect the formation of the austenite structure, but leads to a change in the crystal lattice parameter. [ABSTRACT FROM AUTHOR]

In this paper, using the solid-state reaction technique, high-temperature nanomaterial's superconductors HgBa2Ca2Cu3O8+δ and HgBa2CaCu2O6+δ, have been effectively created. At 850 °C, samples were sintered. By calculating the current and voltage as a function of temperature using the four probes method to determine the transition temperatures Tc(onset) and Tc(offset), the continuous electrical properties were explored. Where it was discovered that for the HgBa2Ca2Cu3O8+δ compound, the electrical resistivity has a gradient Tc(onset) (the beginning) at 145 K but zeroes out at Tc(offset) = 128 K. The temperature Tc(onset) (beginning) for the HgBa2CaCu2O6+δ compound was 137 K, whereas the temperature Tc(offset) was zero at 115 K. Using a Lee disk, thermal conductivity was measured. It was found that the thermal conductivity increased in direct proportion to temperature. The sample of the compound (HgBa2Ca2Cu3O8+δ) (Hg-1223) has a curve that begins at a temperature (40 ° C), thermal conductivity (0.878970388), and ends at a point (0.901118234) with a temperature (280 °C). This curve is higher than the curve of the compound (HgBa2CaCu2O6+δ) (Hg-1212) has a curve that begins at a temperature (40 ° C), thermal conductivity (0.878027444), and ends at a point (0.895530) with a temperature (280 °C). In order to analyze the structural qualities, X-ray diffraction analysis was used. The findings demonstrated that both compounds have a tetragonal crystal structure with distinct differences in the crystal lattice characteristics. [ABSTRACT FROM AUTHOR]

In order to analyze the structural properties of the HgBa2Ca2Cu3O8+δ sample, X-ray diffraction was used. To determine the type of crystal structure, the results showed that the compound has a tetragonal crystal structure. The crystal lattice constants (a, b, c) were calculated with obvious differences in the crystal lattice properties. The crystal size was calculated by four different methods (Scherrer, Williamson-Hall, Halder-Wagner and size-strain plot), which showed the best result using the (Halder-Wagner) method, where the crystal size (C.S=22.27 nm) and determination coefficient (R=0.9903), which is the best method among the four methods for preparing this compound. The titration method of the samples (HgBa2Ca2Cu3O8+δ) was used to find out the percentages of oxygen content (δ) and it was found that the oxygen content was (δ=0.269). And by using the four probes method to determine the transition temperature, it was found that the transition temperature (Tconset) is equal to (147K), where the electrical resistance begins with a strong gradient and becomes zero at the critical temperature (Tcoffset = 128K). The thermal properties were studied using the(Lee's disk) method, the results showed that the thermal conductivity of the sample decreases whenever the temperature is applied to it, as the compound is characterized by a thermal curve that begins to show thermal conductivity at (0.12945) at temperature (313K) and the curve decreases to (0.09888) at temperature (553K). The dielectric properties of the compound were examined using a device (LCR counter) which included: dielectric constant (real and imaginary), loss factor and alternating electrical conductivity, the dielectric properties were studied as a function of frequency and range (50 Hz) to (1 MHz) at room temperature. [ABSTRACT FROM AUTHOR]

Compression experiments are presented on single crystal tantalum in lattice orientations [100], [110], [111] and [1̅49] across a wide range of strain rates from 10−3 s−1 to 104 s−1. Experiments utilised a screw driven load frame and miniature split Hopkinson pressure bar, complementing existing plate impact and Taylor test data. All orientations demonstrated an approximate log-linear relationship between flow stress and strain rate, with an increase in flow stress observed at 104 s−1 in all orientations except [110]. Large variations in flow stress between the various orientations were noted, with Schmid analysis and final state deformation geometry suggesting the dominance of {112} slip. [ABSTRACT FROM AUTHOR]

X-ray diffraction data collected under dynamic compression conditions is extremely challenging to interpret due to non-ideal sources and geometries, in addition to an extreme paucity of data. In this work, we leverage a robust simulated X-ray diffraction tool based within the LAMMPS molecular dynamics code to generate a diverse dataset of accurate and realistic diffraction patterns in a computationally efficient manner. This data is used to train machine learning models that are capable of extracting the crystallographic orientation from diffraction simulation results. Specifically, we have developed a convolutional neural network (CNN) capable of identifying the orientations of the underlying crystal lattice from diffraction patterns. [ABSTRACT FROM AUTHOR]

We modify a theory of flow stress introduced in [6,7,8] for a class of polycrystalline materials with equilibrium and quasy-equilibrium defect structure under quasi-static plastic deformations. We suggest Maxwell-like distribution law for defects (within dislocation-disclination mechanism) in the grains of polycrystalline samples with respect to grain's diameter. Polycrystalline aggregates are considered within single-and two-phase models that correspond by the presence of crystalline and grain-boundary (porous) phases. The scalar dislocation density is derived. Analytic and graphic forms of the generalized Hall–Petch relations for yield strength are produced for single-mode samples with BCC (a-Fe), FCC (Cu, Al, Ni) and HCP (a-Ti, Zr) crystal lattices at T=300 K with different values of the grain-boundary phase. We derived new form of the temperature-dimensional effect. The values of extremal grain and maximum of yield strength are decreased with raising the temperature in accordance with experiments up to UFG region. [ABSTRACT FROM AUTHOR]

Nitride coatings based on high-entropy alloys are a significant extension of the concept of obtaining and using high-entropy materials. The purpose of this work is to analyze the regularities revealed in the study of the structure and properties of multilayer ceramics based on a high-entropy alloy, formed in the form of thin (up to 5 µm thick) coatings on a metal substrate during the deposition of a multi-element metal plasma in a nitrogen atmosphere. A deposition regime was revealed as a result of the performed studies. It makes it possible to form hard (≈50 GPa) coatings based on HEAs nitrides of non-equiatomic composition. It is shown that nitride coatings are multilayer (average layer thickness 47.5 nm) nanoscale (crystallite size 2.5-4 nm) amorphous-crystalline formations. The crystalline component of the coatings has a cubic face-centered crystal lattice, the analog of which is niobium nitride Nb0.88N with a crystal lattice parameter of 0.44588 nm. It has been established that the coatings have hardness varying from 38.4 GPa to 71.7 GPa with an average value of 50.0 GPa; Young's modulus from 430 GPa to 1100 GPa with an average value of E=806 GPa (normalized hardness H/E=0.062). The obtained results can be used in the development of scientific foundations for a new environmentally friendly, fully automated electron-ion-plasma method for the formation of HEAs nitrides with high hardness. [ABSTRACT FROM AUTHOR]

Pure SrTiO3 (STO) was prepared by wet chemical route sintered at 1100oC. The Prepared sample was characterized by FT-IR, UV absorption, XRD and Photoluminescence.FT–IR a spectrum of STO had broad absorption peaks around 1000 cm−1 was due to crystal lattice vibrations. Absorption peaks at 922, 972 and 538 cm−1 were due to stretching vibration of Sr-O and Ti-O bond, respectively. XRD study reveals that STO had a typical perovskite of cubic symmetry indexed by standard JCPDS PDF No. 89-4934. The average crystallite size was calculated by using Scherer's formula and found to be 87.20 nm.UV absoption spectra showed that broad abroption peak in the UV region was around 250–320 nm, as expected. Emission spectra had broad emission in yellowish-green visible region excited by 259nm. It was concluding that prepared nanophosphor is highly recommended for display applications. [ABSTRACT FROM AUTHOR]

When metal macro-objects collide at high speeds, their explosion is possible. The phenomenon of the Coulomb explosion of a metal is well studied. Some new physical processes can be observed against the background of this explosion. Coulomb forces primarily deform the proton matter of nuclei located at the nodes of the crystal lattice. Proton matter attracts neutron matter due to the action of nuclear forces. The shape of the nucleus upon deformation coincides with the shape in the excited state. The excitement is removed by the decay of nuclei in the macro-object. This phenomenon is called shock radioactivity. For its observation, it is important that the collision speed of macro-objects is less than the minimum speed at which the metal explodes. Impact radioactivity is observed for some metals and semimetals, which are noticeably heavier than iron and nickel. When proton matter is deformed, a region of pure neutron matter is formed in nuclei. These neutrons, held together by nuclear forces, can be emitted by the nucleus as new atomic nuclei (neutron nuclei). Neutron nuclei are transmuted through several simultaneous β-decays of neutrons in the composition of the neutron nucleus. This is a consequence of the action of the energy of symmetry. [ABSTRACT FROM AUTHOR]

In this paper we investigated the impurity center local structure by simulation of the structural proprieties of the rare-earth impurity centers RE3+/Bi3+ in lanthanum zirconated La2Zr2O7. Rare-earth ion RE3+/Bi3+ replaces the cation La3+ and determines distortions of the La2Zr2O7 crystal lattice near the impurity center. These distortions characterized by radial and angular displacements of anions were investigated by ab initio calculations. We have employed the MO LCAO approach, in the frame of DFT method as it is implemented in the CRYSTAL17 software for periodic systems, using the hybrid functional PBE0. Since the main contribution to the crystal field on the rare-earth impurity ions comes from its nearest neighbors, the distance "rare-earth ion – ligand" and coordinates of the ligands (oxygen ions) near the impurity centers are calculated. The obtained results are discussed and compared with experimental data and the agreement is quite satisfactory. [ABSTRACT FROM AUTHOR]

An analysis of the effect of brush plating time on SCM440-Ni steel on the crystal structure and hardness has been carried out. The aim of the study was to determine the effect of brushplating time on the crystal structure, hardness and elemental composition of SCM440-Ni steel. SCM440-Ni steel brushplating process at a temperature of 30°C, time variations of 30, 60, and 90 seconds with a pressure of 1 atm. Testing of phase transformation and crystal structure using X-ray diffraction (XRD) technique. Hardness testing using the Vikers Micro scale and chemical composition testing using an Optical Emission Spectrometer. The results of characterization using XRD showed that nickel had been deposited on the surface of the SCM440 steel and several diffraction peaks were formed which indicated the formation of Ni diffraction peaks and the Ni3Fe2 phase with Miller index plane orientations (111), (002), and (022). The optimum diffusion process occurs at 90 seconds and a temperature of 30 C which is indicated by a decrease in grain size, followed by an increase in dislocation density (line defects) and micro-lattice strain. In this case, it affects changes in crystal defects such as grain boundaries, vacancies and dislocations. This results in a change in the lattice strain and crystal size of the nickel coating on SCM440 steel. The results of the hardness test showed that the hardness value increased from the standard SCM440 steel by 336.2HV to 1350 HV from the SCM440-Ni steel with a brush plating time of 90 seconds. The results of the chemical composition test showed that the standard SCM440 steel and SCM440-Ni steel variations in brush plating time of 30 seconds, 60 seconds, and 90 seconds with OES decreased the value of iron elements and increased nickel elements. [ABSTRACT FROM AUTHOR]

It has been known that sound absorptions of vegetation are poor, particularly at a low and medium frequency. In contrast, vegetation is widely used as part of a building or urban city design and development. It is instructive to seek technical ways to enhance sound absorption of vegetation. Thereby, the use of vegetation is more beneficial to noise reduction due to traffic noise. In this study, sonic crystal is introduced near the vegetation to enhance its absorption coefficient. The Finite Element Method (FEM) is employed to model the combined system of vegetation and sonic crystal. At the same time, the resulting calculation in terms of absorption, reflection, and transmission coefficients are discussed. The effect of variation in vegetation length, number of the sonic crystal lattices, and lattice length to the mentioned parameters are also investigated in this study. The result shows enhancement in both sound absorption and reflection of vegetation while the transmission decreased due to reabsorption of reflected sound from sonic crystal. Increasing the vegetation layer length leads to an overall increase in sound absorption, while increasing the number of sound sonic crystal layers leads to a higher gradient of change on absorption coefficient between the bandgap frequency and the non-bandgap frequency. Variation in lattice length leads to variation in the bandgap frequency, where enhancement of sound absorption occurs. Although further investigation is needed, the simulation result shows that the combination of vegetation and sonic crystal is favorable to reduce traffic noise significantly. [ABSTRACT FROM AUTHOR]

The paper considers of the coincidence-site lattice (CSL) model modification, which is used to investigate grain boundary energy of special and arbitrary boundaries. Grain boundary energy is a determining parameter in some inelastic deformation processes, such as recrystallization and grain boundary sliding. The applicability problem of the CSL model modification for various types of boundaries and the problem determination of its parameters (the grain boundary normal, the number of atoms in the considered volume material, and the distance between "coincident" atoms) are considered. The CSL model modification research has shown that the normal orientation does not affect the average grain boundary energy value, the smallest number of atoms on the edge for face-centered cubic crystals lattice is 8, the rational distance between "coincident" atoms is 0,1 of the lattice period. [ABSTRACT FROM AUTHOR]

An Ferroelectric crystal, Triglycine Sulpho Malate crystal (TGSM) was grown using double distilled water as solvent by solution growth technique. The TGSM crystals observed were transparent. The lattice parameters of the TGSM crystals were obtained by single crystal X-ray diffraction technique. The functional groups in the TGSM crystal lattice were confirmed by using FTIR spectral analysis. EDAX studies were to identify the elements in the TGSM crystal. Other studies like UV-visible spectral studies, photoluminescence studies, SHG studies and microhardness studies are done and correlated results with literature. [ABSTRACT FROM AUTHOR]

In this work, we have studied the effect of mass variation of graphene oxide (GO) on the lattice parameter, crystal structure, crystal size, surface morphology, and optical properties of Fe3O4/GO nanocomposite materials. The Fe3O4 was synthesized from the iron sand obtained from Glagah beach located in Kulon Progo, Yogyakarta, Indonesia by using the coprecipitation method. The resulted Fe3O4 was then doped with GO to become Fe3O4/GO nanocomposites by means of ultrasonication method. The composition of the nanocomposites was 5 mg Fe3O4 and 4 mass variations of GO, namely 4 mg, 8 mg, 12 mg, and 16 mg. Each composition was then dispersed in distilled water with a ratio of 1:3 for Fe3O4/GO to distilled water and ultrasonicated for 70 minutes at 35C. Based on XRD data, the mass variation of GO in Fe3O4/GO nanocomposites did not affect the lattice parameters and crystal structure, but did affect the crystal size. The lattice parameter value obtained in Fe3O4/GO is a=b=c=8,3967 A with a cubic crystal structure that has a crystal size of 167,9 nm, 169,1 nm, 158,3 nm, and 62,3 nm corresponding to the GO addition of 4 mg, 8 mg, 12 mg, and 16 mg, respectively. The typical SEM image of the Fe3O4/GO nanocomposite showed the surface morphology of GO in the form of sheets with a length of 6070,52 nm and a width of 2135,8 nm; and Fe3O4 in the form of grain with a grain size of 720 nm. Furthermore, the EDS characterization showed that the chemical composition of the main ingredients of sample 1 was 42,35% C, 39,9% O, and 6,06% Fe with 11,69% impurities, which indicates the success of the production of Fe3O4/GO nanocomposite. In addition, the UV-Vis spectra of the samples showed the change of the band gap of the nanocomposites with the change of GO composition, i.e. 1,94 eV and 2,9 eV for GO composition of 4 mg, 8 mg, respectively. Based on these XRD, SEM-EDS, and UV-Vis characterizations, the Fe3O4/GO nanocomposites have been successfully fabricated with the properties of crystal size and band gap are significantly affected by the addition of GO composition. [ABSTRACT FROM AUTHOR]

The article shows that by forming clusters of impurity nickel atoms in the crystal lattice of silicon, it is possible to suppress various (existing and introduced harmful impurity atoms in the lattice), as well as oxygen atoms, which stimulates the generation of recombination centers and thermal donors. [ABSTRACT FROM AUTHOR]

In this work, the modified williamos-Hall method was used to analysis the x-ray diffraction lines for powder of magnesium oxide nanoparticles (MgO).and for diffraction lines (111),(200),(220),(311) and (222).where by used special programs such as origin pro Lab and Get Data Graph, to calculate the Full width at half maximum (FWHM) and integral breadth (B) to calculate the area under the curve for each of the lines of diffraction.After that, by using modified Williamson –Hall equations to determin the values of crystallite size (D),lattice strain (ε),stress(σ) and energy (U), where was the results are, D=17.639 nm, ε =0.002205, σ=0.517 and U=0.000678 respectively. And then using the scherrer method can by calculated the crystallite size(D) and lattice strain (ε).where by using scherrer equation.the results are D=14.7915 nm and ε=0.00519 respectively, but the modified Williamson –Hall gives more accurate results from the scherrer method. [ABSTRACT FROM AUTHOR]

A study of metal samples from exploited and damaged sections of steam pipelines made of 0.12С-1Сr-1Mo-1V steel after deformation to the formation of zones of stable localization of deformations by the method of electron microscopy was carried out. Specimens without exploitation, after exploitation, but not damaged, and specimens after exploitation before destruction were investigated. As a result of the studies carried out for each sample, the phase composition was determined (qualitatively and quantitatively), and the following parameters of the fine structure were calculated: volume fractions of structural components of steel, scalar ρ and excess ρ± dislocation density, curvature-torsion of the crystal lattice χ, amplitude of internal stresses (shear stress and long-range stresses). All quantitative parameters of the fine structure are determined both in each structural component of steel, and in general for each sample. [ABSTRACT FROM AUTHOR]

It has recently been shown that supersonic 2-crowdions are much more efficient at transferring mass along the crystal lattice compared to classical supersonic crowdions. This is so because, when a 2-crowdion moves, not one, but two atoms move at a high speed simultaneously, and the condition of self-focusing propagation is fulfilled for higher energies of the crowdion. It is interesting to analyze how interatomic potentials affect the self-focusing propagation of 2-crowdions. In this work, we investigate supersonic 2-crowdions in a bcc tungsten lattice by the molecular dynamics method using three different EAM interatomic poten- tials and the LAMMPS software package. It is shown that 2-crowdions propagate over much larger distances in tungsten modeled by potentials with stiffer repulsive cores (short-range parts). [ABSTRACT FROM AUTHOR]

In this manuscript, a sample of the compound with the chemical formula LaBa2Cu3O7 was prepared using solid- state reaction technic. The components of the compound after being mixed was calcination in an electric furnace at 700 °C for 8 hours, then the mixture was pressed into pellets with a diameter of one and a half cm, thickness of 3 mm and sintered at 860 °C for 24 hours. X-ray diffraction was performed. X-ray diffraction (XRD) analysis showed the structure of the sample with a tetragonal structure corresponding to phase La-123.The crystal size of the compounds was studied from XRD analysis was conducted. Scherrer, Size-strain plot, Williamson Hall, Size-strain plot, Halder- Wagner and Degree of crystallinity methods were used to study the individual contributions of crystal sizes and lattice partial strain to isotropic line-widening of all reflectance peaks of the LaBa2Cu3O7 compound. The results showed that all the values calculated by the four different methods are close, as all data points better touch the line of the structure. The crystal sizes estimated from XRD correspond well, while a small difference reflects the spherical shape of the nanoparticles. [ABSTRACT FROM AUTHOR]

This paper presents the results of the full thermodynamic characteristics of paraxylene adsorption in Cs3,17ZSM-5 and Li3,37ZSM-5 zeolites at 303 K.A system consisting of a universal high-vacuum adsorption unit and a Tian-Calvet-type differential modified microcalorimeter connected to it, DAK-1-1A, was used to measure isotherms and differential adsorption heats. The correlation between the adsorption-energetic characteristics was found and the molecular mechanism of paraxylene adsorption in CsZSM-5 and LiZSM-5 zeolites in the whole filling region was revealed. It was found that Li+ cations are located in the screened positions of the ZSM-5 zeolite crystal lattice. Adsorption of the paraxylene molecule leads to the migration of Li+ cations from the zeolite lattice into intersections formed by the intersection of straight and zigzag channels and the formation of ion/molecular complexes of different multiplicity in them. [ABSTRACT FROM AUTHOR]

The injection photodiode based on n+CdS-nCdS-nSi and n+CdS-nCdS-pSi structures was created and the distribution of chemical elements of these structures was studied. It was shown that when a cadmium sulfide film is deposited on the silicon surface, an intermediate layer is formed between the silicon and cadmium sulfide, which helps smooth out the difference between the crystal lattice constants of silicon and cadmium sulfide. It was proved by electron Auger spectroscopy that all obtained cadmium sulfide films have n-type conductivity. [ABSTRACT FROM AUTHOR]

Temperature dependences of the real and imaginary parts of the dielectric permittivity in the ferroelectric Ba1-xSrxTiO3 solid solution are investigated at a frequency of 1 kHz. It was found that an increase in the strontium concentration leads to a shift in the temperature of the dielectric permittivity maximum towards lower temperatures and the dielectric permittivity maximum decreases in height and becomes more diffuse. An increase in the degree of diffusion with an increase in the concentration of strontium atoms in the framework of the composition fluctuations model is explained by the disordering of the distribution of Ba and Sr ions at crystal lattice sites. [ABSTRACT FROM AUTHOR]

The compounds RMn2Si2 (R = Sm, Tb) with tetragonal ThCr2Si2 − type structure was studied. XRD analysis showed the presence of the intermetallic phase other than tetragonal crystal lattice, with a fraction of less than 3%. Experiments on resonant photoemission were performed, and the partial densities of Sm 4f, Tb 4f, and Mn 3d states, which form a valence band in the layered intermetallic RMn2Si2 (R = Sm, Tb), were found. When the energy of the exciting photons coincides with the binding energy of the internal level of the atom, the yield of photoemission from the valence state of this atom is resonantly enhanced by tens times. The main mechanisms of the decay of photoexcited states of rare- earth and transition elements are determined. [ABSTRACT FROM AUTHOR]

Temperature dependences of the real and imaginary parts of the dielectric permittivity in the ferroelectric Ba1-xSrxTiO3 solid solution are investigated at a frequency of 1 kHz. It was found that an increase in the strontium concentration leads to a shift in the temperature of the dielectric permittivity maximum towards lower temperatures and the dielectric permittivity maximum decreases in height and becomes more diffuse. An increase in the degree of diffusion with an increase in the concentration of strontium atoms in the framework of the composition fluctuations model is explained by the disordering of the distribution of Ba and Sr ions at crystal lattice sites. [ABSTRACT FROM AUTHOR]

In the present study, pure and Mn modified Hematite nanoparticles i.e. Fe(2-x)MnxO3 (x = 0, 0.10) were synthesized using auto-combustion technique. The as-synthesized Fe(2-x)MnxO3 (x = 0, 0.10) nanoparticles were characterized by using X-ray Diffractometer (XRD), Field Emission Scanning Electron Microscopy(FE-SEM), and Vibrating Sample Magnetometer (VSM).The structural studies revealed that both the compositions exhibited a rhombohedral crystal structure with space group R-3c. It was observed that the crystallite size of Mn modified Hematite nanoparticles increased due to the intrusion of Mn in the rhombohedral crystal lattice. The crystallite size recorded from XRD studies also confirmed that the grain size increased due to Mn doping in Hematite. Both the compositions showed superparamagnetic behavior with negligible retentivity and coercivity. M-H loops depicted that the value of saturation magnetization increased from 23.24 emu/g to 33.05 emu/g with Mn modification of Hematite nanoparticles. [ABSTRACT FROM AUTHOR]

Within the quasi-viscous mechanism of plastic deformation by flows of nonequilibrium point defects in fields of high local pressure gradients, the features of the propagation of nanobands front of crystal lattice reorientation are studied. The effective viscosity coefficient is estimated depending on the type of point defects (vacancies and interstitial atoms), deformation temperature, the features of the disclination structure and the elastic-stressed state at the front of nanoband propagation. The important role of high local moments or gradient of stress fields in describing the localization of the quasi-viscous deformation mode is established. It is shown that under conditions of high local stress fields, the viscosity of the material can reach values close to the viscosity of amorphous bodies, in particular, of glasses. [ABSTRACT FROM AUTHOR]

Practical significance of nonstoichiometric titanium carbides TiCx in various fields of technology and medicine increase the relevance of the study of both methods used to produce titanium carbide powder and its properties in a wide stoichiometric range. Mechanical treatment is one of the efficient techniques to affect physical and mechanical properties of powder systems. The study investigated the structure, phase composition and parameters of the fine crystal structure of titanium carbide (TiC) powder subjected to mechanical treatment in a ball mill. It is found that at increased duration of milling of the nonstoichiometric titanium carbide powder TiC0.7 the specific surface area of the powder grows from 0.6 to 3.4 m2/g, and the average particle size calculated from it reduces from 2 µm to 360 nm. It is shown that during treatment of the nonstoichiometric titanium carbide TiC0.7 powder, its structural phase state changes. Powder particles consist of two structural components with different atomic carbon-to-titanium ratio: TiC0.65 and TiC0.48. Mechanical treatment of titanium carbide powder decreases microstresses of the TiCx crystal lattice and reduces the CDD size from 55 to 30 nm for the TiC0.48 phase. For TiC0.65 and TiC0.48 phases, increased milling duration acts to decrease the CDD size and to increase the level of the crystal lattice microdistortion. This indicates that, along with powder particle grinding, mechanical treatment provides an increase in particle imperfection. [ABSTRACT FROM AUTHOR]

The change of temperatures of martensitic transformations and parameters of crystal structures in Ti49.8Ni50.2 (at %) alloy samples depending on the value of true deformation (e = 1.84...9.55) during isothermal abc-pressing at temperature 300°C has been studied by in situ X-ray diffraction. It is established that the deformation leads to a slight decrease in the temperature of the beginning of martensitic transformations B2 → B19' and B2 → R but significantly lowers the temperature of the completion of transformations in the final structure B19'. Even the smallest of the introduced deformations leads to a change in the size of the unit cells of all three phases, a multiple increase in the value of micro-strains, and grinding of the coherent scattering regions (CSR) in the crystal lattices of the phases. [ABSTRACT FROM AUTHOR]

Short review of scientific articles of the last years of Russian and foreign researches on studying possibilities of improving mechanical properties of quinary high-entropy alloy (HEA) Cantor of different phase composition in wide range of temperatures is carried out. It is noted that creation of bimodal distribution of grains in sizes by severe plastic torsional strain is one of possibilite. The method of magnetron sputtering and subsequent annealing at 300°C is second they of formation of increased mechanical properties. The effect induced by phase transformation in (CrMnFeCoNi)50 Fe50 alloy obtained by the method of laser additive technology the high mechanical properties reached. The way of improving the mechanical properties at the expense of electron beam processing is noted. Attention is paid to necessity of taking into account the role of entropy, crystal lattice distortions, short-range order, weak diffusion and "cocktail" effect in analysing mechanical properties. [ABSTRACT FROM AUTHOR]

The paper shows the regularities of plastic deformation and fragmentation of pure copper single-crystal after friction stir welding. The obtained data indicate a high role of deformation bands formation with changed orientation of crystal lattice along the contour of the stir zone. Near the stir zone, a larger number of deformation bands are also identified, in which fragmentation of the material into separate grains can already be detected. Near the stir zone, material fragmentation is characterized by the predominance of small-angle boundaries and smooth misorientations in the zone of thermomechanical influence, while in the mixing zone—by more angular boundaries. [ABSTRACT FROM AUTHOR]

The quantitative phase analysis (QPA) of Portland cement X-ray diffraction patterns using the Rietveld method, shows the dominating contribution of Richardson's model of supercells with the water molecules embedded at 2- and 20- degree angles. It is found that the Ca4Si6O14(OH)4(H2O)4 supercell synthesized by using the tobermorite crystal lattice adapted to that of hydrated Portland cement, is stable. Ab initio calculations of the structural, thermodynamic, and mechanical characteristics are performed for the supercells with the full-profile structural characterization. The embedment of water molecules in supercells significantly changes the structural, thermodynamic, and mechanical characteristics of the initial model of the tobermorite crystal lattice. The investigated supercells can be used as reference standards in the QPA of Portland cement curing. [ABSTRACT FROM AUTHOR]

A study of metal samples of sections of steam pipelines made of 0.12C-1Cr-1Mo-1V steel after long-term operation (260 thousand hours) and deformation before the formation of zones of stable localization of deformations by the method of electron microscopy was carried out in this work. Various sections of samples made of 0.12C-1Cr-1Mo-1V steel were investigated, namely, directly in the zones of localization of deformation and at a distance of 3 mm from these zones. The phase composition was determined (qualitatively and quantitatively), as a result of the studies carried out for each sample and the following parameters of the fine structure were calculated: volume fractions of structural components of steel, scalar ρ and excess ρ± dislocation density, curvature-torsion of the crystal lattice χ, amplitude of internal stresses (shear stress and long-range stresses). All quantitative parameters of the fine structure were determined both in each structural component of the steel, and in general for each investigated section of the sample. It was found that not the entire volume of the metal of the sample after a short-term test before reaching a stable localization of deformation has the same microstructure. [ABSTRACT FROM AUTHOR]

Titanomagnetite and ilmenite ores are promising raw materials for the extraction of iron, titanium and vanadium. It is shown that the two-stage method of processing is the most effective in terms of extracting all valuable elements and does not contribute to the formation of man – made waste as with the hydrometallurgical method and the 'Blast furnace – BOF' scheme. At a temperature of 900, 1000 °C in the CO atmosphere, the kinetics of the reduction process is small and the metal phase is not fixed by X-ray phase analysis methods, but some grains have a metal phase. It is shown that the extraction of iron from the ilmenite crystal lattice is accompanied by the release of the TiO2 phase. At a low temperature of 900, 1000, 1100 °C, the dissolution kinetics of TiO2 is small. At a higher temperature of 1200, 1300 °C, the TiO2 phase is dissolved in the ilmenite phase, and the crystal lattice changes to form the FeTi2O5 phase. [ABSTRACT FROM AUTHOR]

We present results of studies of formation mechanism of luminescence centers of the blue range in lithium fluoride crystals. We found that the centers under study are intrinsic defects of crystal lattice formed as a result of a radiation-thermal process in the temperature range much higher than room temperature. Experimental confirmation of simultaneous formation of these centers and F3+ centers, the increase in their concentration during thermal destruction of F3+ centers, and absence of the phonon structure characteristic of R2 centers give basis to attribute the considered centers to a stable configuration of intrinsic radiation defects constituting isomer of F3 center. [ABSTRACT FROM AUTHOR]

Method of C-Mn-Al-Ti-N railway steel quality evaluation based on fractal formalism has been developed. Fractal analysis of acicular ferrite structure by patented fractal method has been performed. The method is based on calculation of mean number of cell and point fractal sizes. Established the one-to-one correspondence between mechanical properties (YTS, UTS, ductility, impact toughness) and fractal sizes of acicular ferrite structure. Experimentally proved that increasing of tempering temperature of acicular ferrite structure from 450 °C to 650 °C lead to increasing of fractal size of acicular ferrite structure from 1.688 to 1.814. It can be explained by reducing of □-Fe crystal lattice distortion. Also during the tempering of acicular ferrite fine carbides precipitates on bainite laths and therefore the length of interface boundaries increases. Such transformations during the tempering process lead to increasing of impact toughness and ductility of acicular ferrite structure and decreasing of YTS and UTS. The evaluation method can be used for prediction of mechanical properties of steels with acicular ferrite structure depends on fractal size of the structure. [ABSTRACT FROM AUTHOR]

Smart materials are materials that are responsive and adaptive to the environment. In recent years, the need for smart material continues to grow. Calcium Carbonate (CaCO3) is one of the potential candidates for the development of smart materials. Results of our previous study in 2018 showed that the dominant component of Tablolong Beach was CaCO3. In this research, a comprehensive XRD analysis of CaCO3 contained in Tablolong Sand is carried out to find out more about the properties of CaCO3 crystals formed directly in nature. Results showed that Aragonite and Calcite were the dominant crystalline phases of CaCO3 in the sand with a total of 95.61% CaCO3 content. Around 4.39% of SiO2 in its Quartz crystal phase was also found in the sand. In addition, the crystallite size of Aragonite and Calcite crystals was calculated by four different methods and found to range from 26.7 nm to 148 nm. Microstrain of CaCO3 crystals was also successfully obtained in three different ways from (in 10−3) 0.3 to 7.7. Finally, the crystal lattice parameters of the Aragonite orthorombic structure were a=0.496281±0.000050 nm, b=0.797216±0.000091 nm and c=0.574605±0.000055 nm, while those of Calcite hexagonal structure were a=b=0.49199±0.00021 nm and c=0.54016±0.00039 nm. [ABSTRACT FROM AUTHOR]

Charged impurity centers in semiconductors are promising objects for the design of quantum devices elements. A relevant problem in this scope is a calculation of rates of transitions due to various mechanisms between different states of such centers. In particular, it is important to thoroughly study nonradiative (phonon) transitions in charged impurities. Special case is associated with local and quasilocal phonon modes. In present work, we consider longitudinal radial oscillations of a crystal lattice with respect to the charged center. We treated the case for small deformation in an isotropic media, in approximation of the absence of any other free charges in the area where the equation is valid. We suppose that continuous media approximation for our equation is valid beyond the first coordination sphere of a lattice. The obtained equation is valid within the scope of approximations made for the consideration of longitudinal radial oscillations for any charged center in covalent semiconductor or dielectric at low free charge carriers concentration. The solution of the equation was numerically obtained. The discrepancies of the solution from free media oscillations are discussed. Our results are important for the calculation of nonradiative electronic transitions in charged impurity centers in dielectric and semiconductor crystals. [ABSTRACT FROM AUTHOR]

In this article, we have been reported the facile, economical and eco-friendly solution combustion method to prepare the vanadium pentoxide (V2O5) without addition of any surfactant. XRD analysis confirms that samples contain the orthorhombic phase of V2O5 with the space group Pmmn. The average crystallite size has been calculated by Debye-Scherrer formula and W-H plot is approximately equal. Micro strain induced in the crystal lattice has been calculated from W-H plot analysis. [ABSTRACT FROM AUTHOR]

The electronic properties of single-layer graphene doped with nitrogen and boron atoms with varying doping consen-trations and configurations have been investigated via firs-principles density functional theory calculation. It is found that the electronic properties of such systems are strongly influenced by the concentration of dopants and their arrangement in the graphene crystal lattice. The effects of doping of a graphene monolayer on its electronic spectrum are studied. These results indicate the possibility of adjusting the band gap by appropriately choosing the concentration of dopants and their location in the graphene crystal lattice. [ABSTRACT FROM AUTHOR]