X-ray Diffraction Profile Analysis Research Articles

X-ray diffraction profile analysis of green synthesized ZnO and TiO2 nanoparticles

ZnO and TiO2 nanoparticles were prepared through a plant-extract mediated hydrothermal synthesis. X-ray diffraction (XRD) study confirmed the crystalline nature and the phase characteristic of the obtained nanoparticles. X-ray diffraction profile analysis models such as Williamson–Hall analysis, size-strain plot and Rietveld analysis were further used in evaluating the microstructural parameters of the obtained materials. The calculated particle size for all the models was in great agreement, with values in the range of 55.46–87.6 nm recorded for ZnO, while for TiO2, the crystallite size was in the range of 33.82–41.9 nm. The calculated crystal microstrain varied based on the model, while the stress in the ZnO and TiO2 nanoparticles was evaluated at 3.8 and 13.7 MPa, respectively. Furthermore, TiO2 nanoparticles had a higher energy density of 8.96 × 10–8 KJ m−3 compared to 7.12 × 10–8 KJ m−3 obtained for ZnO.

Environmentally friendly synthesis of lead halide perovskites using aqueous solutions

In this study, we demonstrate a successful method to synthesize lead halide perovskites (CH3NH3PbX3, X = Br, and I) by immersing lead halides (PbX2) powder in saturated aqueous solutions of methyl ammonium halides (CH3NH3X). Our analysis of reflection spectra and X-ray diffraction profiles confirmed the formation of the lead halide perovskite structures with this exposure process. This approach provides a promising pathway for environmentally friendly perovskite solar cells, eliminating the need for toxic polar organic solvents (for example, DMF, DMSO and so on) commonly employed in conventional perovskite solar cell fabrication.

Vacancies Introduced during the Crystallization Process of the Glass-Ceramics Superionic Conductor, Na3PS4, Investigated by Neutron Total Scattering and Reverse Monte Carlo Method

Sodium solid electrolytes are expected to be safer and more durable than lithium solid electrolytes, which affect the properties of all-solid-state lithium-ion batteries nearing commercialization. The heat treatment of Na3PS4 glass ceramics, a strong candidate for sodium solid electrolytes, results in ionic conductivity exceeding 10–4 S cm–1 at ambient temperature, depending on the heat-treatment conditions. First-principles calculations have suggested that vacancies at Na sites promote ionic conduction; however, the existence of vacancies has not been confirmed through a conventional average structure analysis of X-ray and neutron diffraction profiles or pair distribution functions. In this study, local structure analysis of Na3PS4 glass ceramics using reverse Monte Carlo modeling was performed on the pair distribution function obtained from neutron total scattering measurements during and after heat treatment to identify the vacancy locations that differ from the Na occupation sites. The vacancies in Na3PS4 glass ceramics after heat treatment revealed a more disordered atomic arrangement than Na, suggesting that the vacancies connecting Na occupation sites are most likely responsible for the promotion of Na ion conduction. The control of vacancies in solid electrolytes is essential for the design of practical all-solid-state sodium batteries.

Effect of pulsed magnetic field on retained austenite of quenched 8Cr4Mo4V steel under cryogenic condition

High-intensity pulsed magnetic field was applied to modify the microstructure and mechanical propertis of quenched 8Cr4Mo4V bearing steel under the cryogenic environment. The microstructual transformation in 8Cr4Mo4V bearing steel was investigated by X-ray diffraction (XRD), Vibrating sample magnetometer (VSM) and Electron Backscatter Diffraction (EBSD) and so on. The results revealed that individual deep cryogenic treatment (DCT) promote the transformation from retained austenite (RA) in quenched steel to martensite. However, this phase transformation will be inhibited by coupling high-intensity magnetic field with deep cryogenic treatment (MDCT). For instance, the relative reduction of RA content in DCT samples was 10 ± 2%, while that in MDCT samples was 3 ± 3%. Furthermore, the modified Williamson-Hall method was utilized to estimate the dislocation characteristics based on XRD profile analysis. It exhibited that the proportion of edge dislocation significantly decrease from 61.8% to 43.7% by DCT, while this type of dislocation remains almost unchanged after MDCT. Moreover, the microhardness of quenched 8Cr4Mo4V steel became more uniform after MDCT than that of DCT. It can be indicated that the martensite transformation is blocked and carbon cluster is dissolved under the condition of coupling pulsed magnetic field treatment.

On the possibility of fabricating fully austenitic sub-micron grained AISI 304 stainless steel via equal channel angular pressing

The paper concerns possibility of increasing yield and ultimate stress of austenitic stainless steels by equal channel angular pressing (ECAP). To this end, an AISI 304 stainless steel subjected to eight passes of ECAP in a 105◦ die at 350◦ C. The evolution of microstructure as a function of induced plastic strain (number of passes) was studied in different length scales using light and scanning transmission electron microscope (STEM). An insight into fine details of dislocation structure was possible via X-ray diffraction profile analysis. Changes in the structure of processed samples were correlated with their mechanical properties as determined by tension tests and microhardness measurements. Light microscopy revealed a shear banded microstructure. STEM observations demonstrated co-existence of three types of grain structure: (a) short elongated grains/subgrains of 71 nm average width formed within the shear band regions, (b) a mixture of coarse (200–350 nm in size) and nanocrystalline (15– 70 nm) equiaxed grains developed outside the shear bands, and (c) nano-twin lamellae of 3–20 nm width inside nanocrystalline grains. XRD peak profile analysis using modified Warren–Averbach approach yielded dislocation density as ρ = 4.71 × 1015 m−2 after eight passes. ECAP-induced changes in the microstructure led to a remarkable increase in yield strength of the alloy (YS=1498 MPa, about 3.5 times the initial amount). At the same time, a moderate ductility of εf = 12% was maintained, primarily due to a large post-necking elongation. This behavior was explained by an increase in the strain rate sensitivity of ECAP-ed material in combination with the contribution from transformation induced plasticity, TRIP effect, caused by formation of ∼ 22 vol% martensite during room temperature straining.

X-ray diffraction profile analysis of martensitic Ti6Al4V (ELI) parts produced by laser powder bed fusion

The quantification of the density of defects in materials through non-destructive methods is of great interest to scientists and engineers. X-ray diffraction (XRD) peak profile analysis is a valuable method that is often used to reveal important microstructural information, such as defects present in crystalline materials as well as crystallite size. In this study, the broadening of XRD peaks of martensitic Ti6Al4V (ELI) produced by laser powder bed fusion (LPBF) was studied following modified Williamson-Hall (MWH) and Warren-Averbach (WA) analytical methods. The level of defects in martensitic LPBF Ti6Al4V (ELI) was found to drastically reduce by at least 73% after exposing the material to stress-relieving heat treatment.

X-ray diffraction (XRD) profile analysis and optical properties of Klockmannite copper selenide nanoparticles synthesized via microwave assisted technique

In this study, copper selenide (CuSe) nanoparticles (NPs) were prepared using the microwave irradiation technique. The effect of the irradiation time on the structural properties of CuSe NPs was investigated. The XRD results confirms the formation of the hexagonal (Klockmannite) structure of CuSe NPs. Different X-ray diffraction profile analysis techniques comprising strain-size plot (SSP), Scherer’s method (S-M), Monshi-Scherer’s method (MSM), Halder-Wagner (H–W) technique, and Williamson-Hall technique (WHM) were employed to examine the effect of irradiation time on the particle size as well as intrinsic strain of CuSe NPs using XRD peak broadening analysis. Uniform deformation model, uniform stress deformation model, as well as uniform energy density deformation model of Williamson-Hall technique were used to calculate the average crystallites size of CuSe NPs. Essential physical variables involving stress and energy density were also computed. Also, field emission scanning electron microscope (FESEM) in addition to atomic force microscopy (AFM) were further used to determine the mean particle size of CuSe NPs depending on varying irradiation time. The obtained results were found to be in agreement and comparable with the results of XRD profile analysis methods. Raman spectroscopy revealed three vibrational bands which are ascribed to the CuSe vibrational modes. Furthermore, the optical characteristics of the synthesized CuSe NPs were also investigated. The result obtained revealed a decrease in the optical bandgap from 2.43 to 2.71 eV with increase in irradiation time. Photoluminescence study revealed two peaks at 530, and 610 nm respectively. Therefore, it can de deduced that inclusion of intrinsic strain play an important role on the estimation of CuSe NPs size and microstrain of CuSe NPs synthezed vi microwave assisted synthesis technique.

Insight into dislocation activity during ECAP processing of AISI 304 stainless steel studied by X-ray diffraction profile analysis

Insight into dislocation activity during ECAP processing of AISI 304 stainless steel studied by X-ray diffraction profile analysis

Structural Transformations in Cold-Rolled Austenitic Chromium-Nickel Steel Studied by Synchrotron X-Ray Diffraction and Peak Profile Analysis

Structural Transformations in Cold-Rolled Austenitic Chromium-Nickel Steel Studied by Synchrotron X-Ray Diffraction and Peak Profile Analysis

Evolution of Face-Centered Cubic Ti Alloys Transformation by X-ray Diffraction Profile Analysis in Mechanical Alloying

Four titanium alloys (Ti-Ta, Ti-Ta-Sn, Ti-Ta-Mn, and Ti-Nb-Sn) were synthesized by mechanical alloying (MA) in a planetary mill in different times between 2 h and 100 h. The microstructure characterization was made by X-ray diffraction (XRD), in which the Rietveld method was applied to analyze the diffraction patterns. The study demonstrated that after short milling times between 2 h and 30 h, the fraction of hexagonal close-packed (hcp) phase decreases; at the same time, the formation of body-centered cubic (bcc) and face-centered cubic (fcc) Ti phases are promoted. Additionally, after 30 h of MA, the full transformation of hcp-Ti was observed, and the bcc-Ti to fcc-Ti phase transformation took place until 50 h. The results suggest that the addition of Ta and Sn promotes the fcc-Ti phase formation, obtaining 100% of this phase at 50 h onwards, whereas Nb and Mn show the opposite effect.

Interactions between soluble soybean polysaccharide and starch during the gelatinization and retrogradation: Effects of selected starch varieties

This study shows that soluble soybean polysaccharide (SSPS) has different anti-retrogradation effects on different types of starches and demonstrates the mechanism. Maize starch (MS), wheat starch (WS), rice starch (RS) and tapioca starch (TS) were chosen to investigate the pasting and retrograding characteristics with low-field nuclear magnetic resonance (LF-NMR), rapid visco-analysis, X-ray diffraction (XRD), and texture profile analysis (TPA). A 4% SSPS solution lowered the pasting viscosity of starch systems and tightened the interstitial water (T22) that dominated the starch network (LF-NMR). After 14-day refrigeration, XRD results indicated that SSPS reduced the relative crystallinities of MS and WS, increased that of TS, but had little effect on RS. The different interaction patterns between SSPS and starch led to the differences in retrogradation crystal structure and the formation of V-type structures inhibited the starch retrogradation (MS and WS). The minimal anti-retrogradation effect of SSPS on RS can be explained by its small starch granule size and fuzzy original morphology. The special non-porous structure of TS and the possible electrostatic interaction with SSPS might accelerate the retrogradation process. In addition, SSPS could soften the hardness of MS and WS gels but promote the gelatinization of TS (TPA). Confocal laser scanning microscopy (CLSM) images proved the coating capacity of SSPS. Thus, the coating ability of SSPS on starch granules, the competition effect of SSPS on starch for available water, and the possible molecular interactions between SSPS and starch could be responsible for these results.

Crystal Structure Analysis of Top Dross in Molten Zinc Bath by First Principles Calculation and Synchrotron X-ray Diffraction

In a molten zinc bath in a continuous galvanizing line, the top dross particles crystallize as a Zn-containing intermetallic Fe2Al5 compound, which generates surface defects in the final product by easily adhering to the steel sheets. The present study focused on analysis of the crystal structure of a top dross by first principles calculation and synchrotron X-ray diffraction of the top dross prepared in a laboratory. The following results were obtained: first principles calculation on the top dross suggested that two Al atoms at four of the partially occupied Al sites in the Fe2Al5 structure proposed by Mihalkovič et al., were replaced by two Zn atoms. In addition, the Al atoms at both the types of partially occupied Al sites in Fe2Al5 proposed by Burkhardt et al., were equally replaced by Zn atoms. The proposed crystal structure of the top dross was verified by conducting X-ray diffraction profile analysis using RIETAN-FP simulations as well as the experimentally determined lattice constant of the Zn-containing top dross.

A microstructure study of colloidal gold nanoparticles by X-ray diffraction line profile analysis

We present the colloidal synthesis of gold nanoparticles (Au NPs) using the chemical reduction of gold precursors by changing the reducing agent (Na3C6H5O7) volume. We aimed at achieving different particle sizes, morphologies, and defect structures. The modified process impacted the overall synthesis time and nanoparticles' microstructures. We used X-ray diffraction profile analysis (XPA) and transmission electron microscopy (TEM) to follow the nanoparticles’ size and lattice strain details. The NPs' size distributions agree well between the indirect XPA and TEM direct measures. Nanocrystal shapes change from triangular, octahedral, and decahedral to hexagonal plate-like; it shows how the NPs minimize their energy formation by creating defects and well-defined crystallographic directions, including crystal fusion. The combined effects of dislocations, twin boundaries, and surface tension add together to broaden the diffracted line profiles. In particular, the density of dislocation and twin boundaries increase toward the smaller NPs.

XRD Line Profile Analysis of Ball Milled ODS Ferritic Steel Powder Consolidated by Hot Isostatic Pressing

In this study, an ODS ferritic steel powder of composition Fe–12Cr–2W–1Zr–0.2Y (in wt %) was mechanically alloyed in a planetary ball mill, until the proper solid solution was established and consolidated by hot isostatic pressing. Basic microstructure features, in terms of the nature, density of the dislocations, lattice parameter and lognormal domain sizes distribution,—were determined by X-ray diffraction profile analysis, using the recent, powerful whole powder pattern modelling approach. XRD analysis revealed that microstructure during ball milling evolved towards the nanocrystalline state made of very fine, narrowly dispersed crystallites with strongly correlated dislocation structure of extensive number density of dislocations reaching almost 1017 m–2. Mean coherent domain size was estimated using both whole powder pattern modelling and modified Williamson–Hall methods, which yielded 9.5 and 7.5 nm, respectively. Powder consolidation induced crystallite growth accompanied with restrained drop in dislocation density. The anisotropic strain broadening of bcc iron diffraction peaks was taken into account by incorporating the dislocation contrast factor, directly related to elastic constants of material and to the dislocation slip system.

Considerable improvement in elastic moduli and the underlying mechanism of Al-Cu-Zn alloy subjected to aging treatments

In this study, considerable improvement in elastic moduli has been found for an Al-4 mass% Cu-20 mass% Zn alloy during aging at 373, 408 and 443 K. Young's modulus and shear modulus were increased by 5.9 GPa and 2.6 GPa maximum from those in the as-quenched condition, demonstrating non-negligible 10% improvement achieved by the conventional aging treatment. Electrical conductivity was also increased, and correlated to volume fractions of metastable ε-CuZn4 determined by Rietveld analysis of X-ray diffraction profiles. Using a proposed fractional function derived from the Al-Cu-Zn phase diagram, elastic moduli of the alloy were well predicted according to the rule of mixtures, suggesting not only was the estimation of volume fractions from electrical conductivity appropriate, but the computed elastic moduli of ε-CuZn4 in [1] were also accurate. This function is not only convenient in estimating Vf of ε-CuZn4 by non-destructive, intermittent and instant electrical conductivity measurement, but also is universal for any alloy system if the residual solute concentrations in the matrix decrease with a definite relation during aging, as in the case of ε-CuZn4 formation.

Heavy ion irradiation damage in Zr3(Al0.9Si0.1)C2 MAX phase

A Zr3(Al0.9Si0.1)C2 MAX phase-based ceramic with 22 wt.% ZrC and 10 wt.% Zr5Si3 has been irradiated with 52 MeV I9+ ions at room temperature, achieving a maximum dose of 8 displacements per atom (dpa). The response of this MAX phase-rich material to irradiation has been studied using scanning electron microscopy, transmission electron microscopy and X-ray diffraction techniques. Post-irradiation examination of the material revealed a number of crystalline changes to the MAX phase. At low doses, Zr3(Al0.9Si0.1)C2 maintained a high degree of crystallinity, while at the highest doses, its degree of crystallinity was reduced significantly. A number of radiation-induced phase transformations were observed, including the decomposition of Zr3(Al0.9Si0.1)C2 into ZrC and other phases, and the formation of β-Zr3(Al,Si)C2, a MAX phase with a rearranged stacking sequence. Microstructural examination revealed that the majority of the extended defects in Zr3(Al0.9Si0.1)C2 lie in the (0001) basal planes. Analysis of X-ray diffraction profiles after heat treating the 8 dpa-irradiated material for 1 h at 300 °C and at 600 °C showed that there were only subtle changes to the profiles relative to that of the 8 dpa-irradiated material which had not been heat treated. Overall, the experimental results of this study show that the Zr3(Al0.9Si0.1)C2 MAX phase responds less well to irradiation relative to other MAX phases irradiated with high energy heavy ions at room temperature.

Granularity-induced plastic deformation mechanism of pure polycrystalline cubic boron nitride

Combined X-ray diffraction(XRD) profile analysis and HRTEM observation, a method for exploration of plastic deformation in pure polycrystalline cubic boron nitride (PcBN) samples with sizes of primary cBN powders was developed. XRD profile results showed that the coarse-grained PcBN exhibited a larger micro-strain ε, a greater deformation stacking faults probability fD, which was an order of magnitude larger than that of fine-grained PcBN, but a smaller twin stacking faults probability fT. It was deduced that the plastic deformation of the coarse-grained PcBN was dominated by stacking faults and mechanical twins mode, which would result in strain strengthening and then recrystallization. While the manner of growth twins was the mainly modes of fine-grained PcBN by phase transform, especially utilized the curled SP2 structure as a basis for a cubic structure nucleation. Fundamental plastic deformation principles of the ultrafine polycrystalline cBN was crucial for the field of high-precision cutting tools.

Electrochemical hydrogen storage behaviors of as-milled Mg–Ti–Ni–Co–Al-based alloys applied to Ni-MH battery

In the study, the hydrogen storing materials Mg–Ni-based Mg50-xTixNi45Al3Co2 (x = 0, 1, 2, 3, 4) + 50 wt% Ni (named Mg50-xTixNi45Al3Co2 (x = 0–4) + 50Ni) with nanocrystalline and amorphous structures were fabricated by the method of mechanical milling and designed for the negative electrode of Ni–MH batteries. The investigation aims at researching the function of Ti dosage on the electrochemical hydrogen storing characteristics and microstructure of the experimental specimens. The analysis of X-ray diffraction profiles and Scanning Electron Microscope images determines that the experiment specimens contain the major phase Mg2Ni and the minor phase MgNi2. The observation of TEM images reveals a fact that the specimens after ball-milling treatment consist of the nanocrystal and amorphism structures. The electrochemical tests show that as for the samples after ball-milling treatment, the discharge capacities of them gain the utmost value at the first circulate without activation treatment, and the increase of Ti dosage brings on an evident rise in the specimens’ discharge capacity and cycle stability. Concretely, as the Ti content alters from 0 to 4, the discharge capacities of the as-milled (20 h) sample increase from 405.0 to 519.4 mAh/g and capacity retention rate of 100th circulate (S100 = C100/Cmax) augments from 45% to 72%. What’s more, a series of measurements, such as the high rate discharge ability (HRD), the electrochemical impedance spectrum (EIS) as well as Tafel polarization curves etc. show that the electrochemical kinetics performances of as-milled specimens in this experiment have a trend of increasing first and then decreasing with the addition of Ti element.

Effects of In3+ site occupancy on the magnetic properties of M-type strontium hexaferrites

Effects of nonmagnetic indium ion substitution on magnetic properties of M-type strontium hexaferrites SrFe12-xInxO19 (x=0, 0.25, 0.5, 0.75, and 1) have been studied by crystallographic and magnetic measurements. Samples were prepared by citric auto-combustion method. Rietveld analysis of X-ray diffraction profiles showed that the samples were single phase with the space group P63/mmc and lattice constants a and c increased linearly with In3+ content. Mössbauer spectra showed that In3+ mainly replaced Fe3+ ions in 4f2 sites and that 12k subspectra split into two distinct components 12k1 and 12k2. Analysis of hysteresis curves showed that while the coercive force and the magnetic anisotropy constant decreased thru the whole doping range x, the saturation magnetization first increased until x=0.5 and decreased thereafter. This behavior was explained by the existence of two competing interactions in terms of nonmagnetic indium substitution.

Dislocation Structure in Hot Deformed Al-Zn-Mg Alloy by X-ray Line Profile Analysis.

The microstructure of extruded Cu-free Al-Zn-Mg alloy is studied. Hot torsion tests are performed on a Cu-free Al-Zn-Mg alloy to investigate the effect of large strain deformation on the dislocation behavior. The dislocation structure is characterized by X-ray diffraction profile analysis, and the effective stress-strain curves are obtained by hot torsion tests. The dislocation density at low deformation temperature is found to be higher than that at high deformation temperature. The dislocation density of the alloy increases gradually up to ε = 1 with increasing strain and does not change significantly during further deformation.