Intensity Of Diffraction Lines Research Articles

Evidence for phonon hardening in laser-excited gold using x-ray diffraction at a hard x-ray free electron laser

Studies of laser-heated materials on femtosecond timescales have shown that the interatomic potential can be perturbed at sufficiently high laser intensities. For gold, it has been postulated to undergo a strong stiffening leading to an increase of the phonon energies, known as phonon hardening. Despite efforts to investigate this behavior, only measurements at low absorbed energy density have been performed, for which the interpretation of the experimental data remains ambiguous. By using in situ single-shot x-ray diffraction at a hard x-ray free-electron laser, the evolution of diffraction line intensities of laser-excited Au to a higher energy density provides evidence for phonon hardening.

Identification of Sildenafil Compound in Selected Drugs Using X-ray Study and Thermal Analysis

Twelve drugs containing sildenafil compounds (sildenafil citrate and sildenafil base) were examined using X-ray studies and thermal analysis. According to the manufacturer's information, the presence of sildenafil was confirmed in all investigated drugs. The positions of diffraction lines (value of 2θ angle) agree with the patterns presented in the ICDD database, Release 2018 (ICDD-International Centre of Diffraction Data). The difference expresses the agreement in the position of the diffraction line between the tested substance and the standard. A good agreement is when this difference is less than 0.2°. The values of interplanar distances dhkl are also compatible with the ICDD database. It indicated that the drug examined was genuine. Because all drugs are mixtures of different substances (API and excipients), the various diffraction line intensities were detected in all observed X-ray images for the tested drugs. The intensity of the diffraction line depends on many factors, like the amount of substance, coexisting phases, and mass absorption coefficient of the mixture. The thermal analysis confirmed the results obtained by the X-ray study. On DSC curves, the endothermic peaks for sildenafil compounds were observed. The determined melting points of sildenafil compounds corresponded to the values available in the literature. The results gathered by connecting two methods, X-ray study and thermal analysis, can help identify irregularities that may exist in pharmaceutical specimens, e.g., distinguishing genuine from counterfeit products, the presence of a correct polymorph, a lack of active substance, an inaccurate amount of the active substance, or excipients in the tested drug.

Forced hydrolysis of FeCl3 solutions in the presence of Cr3+ ions

Forced hydrolyses of FeCl3 solutions in the presence of Cr3+ ions without alkali addition were investigated at 160 and 200 °C. These precipitation systems were compared to corresponding reference systems. The isolated precipitates were characterized with XRD, 57Fe Mössbauer, FT-IR, FE SEM and photocatalytic measurements. Although chromium was not detected by EDS (Energy Dispersive X-ray Spectroscopy), the analysis of samples precipitated in the presence of Cr3+ ions showed several effects which can be attributed to the presence of these ions in the starting solutions. These effects are specifically well pronounced for samples obtained at 200 °C. For the highest concentration of Cr3+ ions and upon heating at 200 °C the transformation kinetics β-FeOOH to α-Fe2O3 was impeded. Relative intensities of prominent diffraction lines 104 and 110 of α-Fe2O3 changed as a result of the presence of Cr3+ ions. Changes in the size and formation of lemon-like particles instead of cube-like α-Fe2O3 particles were also noticed. The presence of Cr3+ ions in hydrolysing FeCl3 solution influenced the photocatalytic degradation of rhodamine B. Since no specific adsorption of Cr3+ ions occurred in the acidic pH medium, it was inferred that traces of Cr3+ ions enter into the structural tunnels of β-FeOOH crystals. The associates Cl−-Cr3+ are formed, which in the next step destabilize the crystal structure of β-FeOOH particles. Cr3+ ions leave the crystal structure upon dissolution of β-FeOOH. It can be assumed that α-Fe2O3 crystals start to grow on very fine and thin β-FeOOH crystallites which were not completely dissolved, but were previously affected by Cr3+ ions.

Influence of surface ultrasonic impact treatment on texture evolution and elastic properties in the volume of Zr1Nb alloy

The study is devoted to examination of the features of influence of ultrasonic impact treatment (UIT) on the evolution of texture and the changes of elastic parameters in the volume of specimens of Zr1Nb alloy with preliminary-formed strong crystallographic texture. In this case the bulk-wave ultrasonic velocities (vij) in the orthogonal directions in the different sections of the specimens were measured by the automatic US apparatus in initial state (after high-temperature rolling) and after UIT. The density (ρ) of the specimens was also measured in initial and deformed states. Based on the obtained results orientation distribution coefficients (Wij0) were calculated, complete pole figures were plotted, relative intensity of diffraction lines of the basal plane (ΔІ(0001)) and Kearns parameters (fi) were determined. The extreme values of Young (E) and shear (G) moduli, Poisson ratio (η) and their anisotropy were also calculated for different sections of the treated specimens. It is shown that UIT in applied regime changes the texture and elastic parameters in all specimen volume. Pole figures (0001) after UIT keep the view typical for rolled HCP alloys with ratio c/a < 1.633. The clear qualitative correlation between the texture and elastic parameters of the specimens in initial state and after UIT in their different sections is defined. The revealed features indicate that the evolution of crystallographic texture of Zr1Nb alloy specimens is a result of the depth nonuniformity of plastic deformation accumulated during the UIT process. The results are in agreement with available literature data. The effectiveness of applied US method and equipment for layer-by-layer analysis of the texture and elastic characteristics in the volume of spatially inhomogeneous materials subjected to directional surface thermomechanical treatment is shown.

Detecting and determining the nature of an anomalous x-ray optical effect in two-Layer substrate–coating systems

The authors have detected an anomalous X-ray optical effect in the Ni(1−x)Wx/TiN system, which consists of a rise in the intensity of certain diffraction lines of the substrate with increasing coating thickness. Based on the observed effect, this article has conceptualized the optimization of the architecture of two-layer systems with a substrate of TiN-coated NiW paramagnetic alloys, which provides an increase in the current-carrying capacity of second generation high temperature superconductors (2G HTS).

Quantitative Phase Analysis by X-ray Diffraction—Doping Methods and Applications

X-ray powder diffraction is an ideal technique for the quantitative analysis of a multiphase sample. The intensities of diffraction lines of a phase in a multiphase sample are proportional to the phase fraction and the quantitative analysis can be obtained if the correction for the absorption of X-rays in the sample is performed. Simple procedures of quantitative X-ray diffraction phase analysis of a multiphase sample are presented. The matrix-flushing method, with the application of reference intensities, yields the relationship between the intensity and phase fraction free from the absorption effect, thus, shunting calibration curves or internal standard procedures. Special attention is paid to the doping methods: (i) simultaneous determination of the fractions of several phases using a single doping and (ii) determination of the fraction of the dominant phase. The conditions to minimize systematic errors are discussed. The problem of overlapping of diffraction lines can be overcome by combining the doping method (i) and the individual profile fitting method, thus performing the quantitative phase analysis without the reference to structural models of particular phases. Recent suggestions in quantitative phase analysis are quoted, e.g., in study of the decomposition of supersaturated solid solutions—intermetallic alloys. Round Robin on Quantitative Phase Analysis, organized by the IUCr Commission on Powder Diffraction, is discussed shortly. The doping methods have been applied in various studies, e.g., phase transitions in titanium dioxide, biomineralization processes, and phases in intermetallic oxide systems and intermetallic alloys.

Influence of Expansion on Properties and Microstructure of Calcium Silicate Composite Material

The aim of the research was verification of influence of aeration and influence of aluminum powder on microstructure and physical mechanical properties of calcium silicate composite material. At the same time, influence of various dosages of alternative raw materials on porous structure of the composite was examined. Tested raw materials are not the ones commonly used in the technology of manufacture of calcium silicate composites, for example chamotte blocks, Lining of silica and foundry sand. It was found that influence of aeration of calcium silicate composite causes reduction of compressive strength by roughly 85%. At the same time, volume weight drops by 50%. As a consequence of the expansion, intensity of diffraction lines of tobermorite detected by X-ray diffraction analysis is reduced because of reaction of aluminum powder with calcium hydroxide. It was found that there is dependency between the amount of replacement of silica sand with foundry sand and silica, and intensity of tobermorite diffraction lines, where the intensity of the diffraction lines was reduced with increased amount of replacement.

Polymorph Selection via Sublimation onto Siloxane Templates

Diphenylurea (PU) crystallizes via slow evaporation from a range of solvents as phase pure α-PU or in a concomitant mixture with the less stable β-PU phase. Sublimation onto glass also yields α-PU in high phase purity. In contrast, sublimation onto siloxane-coated glass templates with various terminal groups (e.g., isocyanate, acetate, bromine) resulted in primarily β-PU. Scanning electron microscopy showed that the individual crystals on siloxanes exhibit a range of different morphologies (e.g., plates, needles, hollow tubes, spirals) which appear to be influenced by the terminal siloxane functionality. Under extended sublimation times (>5 h), mixtures of β and α become apparent on most siloxanes. Grazing incidence X-ray diffraction studies showed that the β:α ratio changes as a function of distance from the siloxane, with more α-PU appearing at higher angles. Diffraction line intensities also indicate strong preferred orientations for β-PU crystallites within the polycrystalline layer with the fastest growth direction (b-axis) parallel to the template, but more varied orientations for α-PU. This suggests α-PU may nucleate elsewhere in the sublimation apparatus rather than on the β-coated siloxane. This study demonstrates the utility of template-directed sublimation methods as a way to engineer metastable phases but also illustrates some of the challenges associated with achieving high phase purity on templates with limited surface area.

Characteristics of Thin Cu Films Electrodeposited On Textured Ni-Co Substrates

An attempt has been made to study the effects of current density and the texture of the underlying substrate on electrodeposited copper. For this purpose five Ni-Co alloys, Ni-10 Co, Ni-20 Co, Ni-30 Co, Ni-40 Co and Ni-60 Co, in the cold rolled as well as in the annealed conditions, were used as substrates. Acid copper sulfate solution was used to deposit thin Cu layers on the substrates, using a Cu plate as anode, at four different current densities, 1, 10, 30 and 50 mA/cm2. The thickness of the electrodeposited Cu layer increased nearly linearly with current density, but was independent of the texture and composition of the underlying substrate. In general, the X-ray diffraction line intensities for the deposited Cu layer sharpened and those for the substrate Ni alloys weakened with increase in current density. The textural developments in the Cu deposits appeared to be quite independent of the textures as well as the compositions of the substrate materials. The deposited Cu layers did not inherit the textures of the substrates at the lower current densities, and also developed their own textures at higher current densities. The Cu (220) peak ultimately became the strongest XRD peak for the electrodeposited layer. The surface roughness of the deposited layers was distinctly smoother for the annealed substrates, as compared to the cold rolled Ni-Co alloys.

Structural, dielectric and impedance spectroscopic studies of Ni0.5Zn0.5−xLixFe2O4 nanocrystalline ferrites

Nanocrystalline lithium substituted Ni–Zn ferrites with composition Ni[Formula: see text]Zn[Formula: see text]Li[Formula: see text]Fe2O4 ([Formula: see text] = 0.00–0.25 in steps of 0.05) were synthesized by the citrate gel auto-combustion method and were sintered at 1000[Formula: see text]C for 4 h in air atmosphere. The structural, dielectric, impedance spectroscopic and magnetic properties were studied by using X-ray diffraction, impedance analyzer and vibrating sample magnetometer respectively. The X-ray diffraction patterns confirm that all samples exhibit a single phase cubic spinel structure. Suitable cation distribution for all compositions has been proposed by using the X-ray diffraction line intensity calculations and the theoretical lattice parameter for each composition was observed in close agreement with the experimental ones and thereby supporting the proposed distribution. An increase in the saturation magnetization was observed up to [Formula: see text] = 0.10 level of Li[Formula: see text] substitution and thereafter magnetization reduced for higher concentrations to the highest level of Li[Formula: see text] substitution. The dielectric constant and the DC resistivity of Ni–Zn–Li ferrites were noticed to decrease with increase in the Li[Formula: see text] ion concentration. The impedance spectroscopic studies by using the Cole–Cole plots were studied in order to obtain the relaxation time, grain resistance and grain capacitance. AC conductivity initially remained almost independent of frequency for lower frequencies and thereafter for higher frequencies the AC conductivity increased with increase of Lithium concentration.

On the Relationship between Structural-Elastic Properties of Co-Zn Ferrites at 300 K

The structural - elastic properties correlations have been studied for polycrystalline spinel ferrite system, ZnxCo1-xFe2O4, x = 0.0-0.6, at 300 K. The cation distribution formulae determined from X-ray diffraction line intensity calculations are used to calculate bulk modulus (Ko) in particular and Young′s modulus (E0), rigidity modulus (G0), longitudinal modulus (L0) and Lame′s constant (λL0) in general. The longitudinal wave velocity (Vl0) and transverse wave velocity (Vso) computed from empirical relation based on X-ray density and mean atomic weight is used to calculate L0 and G0 respectively. The applicability of the heterogeneous metal mixture rule for theoretical estimation of elastic constants has been tested. The results are compared with elastic moduli determined from conventional ultrasonic pulse transmission technique and causes for the observed difference between the two have been discussed.

Quantitative phase analysis by X-ray diffraction – Simple routes

&lt;p&gt; The elemental composition of a multiphase material can be obtained by means of chemical and spectroscopic techniques. However, these techniques face a great difficulty in distinguishing the chemical identity of the phases present in the material and in derivation of the fractions of particular phases. X-ray powder diffraction seems to be an ideal technique for the analysis of a multiphase material. Each crystalline phase of the material gives its characteristic diffraction pattern independently of the other phases; this fact makes it possible to identify the phase of interest and to determine its fraction. The intensities of diffraction lines of a given phase are proportional to its fraction and an appropriate quantitative analysis can be performed after the application of the correction for the absorption of X-rays in the material.&lt;/p&gt;&lt;p class="IUCrfigurecaption"&gt; The principles of quantitative X-ray diffraction phase analysis of a multiphase material are presented, with a special attention paid to the doping methods. The following methods are described: (&lt;em&gt;i&lt;/em&gt;) determination of the fraction of a phase using repeated dopings, (&lt;em&gt;ii&lt;/em&gt;) determination of the fraction of a phase using a single doping, (&lt;em&gt;iii&lt;/em&gt;) simultaneous determination of the fractions of several phases using a single doping; (&lt;em&gt;iv&lt;/em&gt;) determination of the fraction of the dominant phase. The applicability of the doping methods is stated and the optimum conditions to minimize systematic errors are discussed. Recent approaches in quantitative X-ray diffraction phase analysis are also mentioned in short.&lt;/p&gt;

Raman and Mossbauer spectroscopy and X-ray diffractometry studies on quenched copper-ferri-aluminates.

Four spinel ferrite compositions of the CuAl(x)Fe(2-x)O4, x = 0.0, 0.2, 0.4, 0.6, system prepared by usual double-sintering ceramic route and quenched (rapid thermal cooling) from final sintering temperature (1373 K) to liquid nitrogen temperature (80 K) were investigated by employing X-ray powder diffractometry, (57)Fe Mossbauer spectroscopy, and micro-Raman spectroscopy at 300 K. The Raman spectra collected in the wavenumber range of 100-1000 cm(-1) were analyzed in a systematic manner and showed five predicted modes for the spinel structure and splitting of A1g Raman mode into two/three energy values, attributed to peaks belonging to each ion (Cu(2+), Fe(3+), and Al(3+)) in the tetrahedral positions. The suppression of lower-frequency peaks was explained on the basis of weakening in magnetic coupling and reduction in ferrimagnetic behavior as well as increase in stress induced by square bond formation on Al(3+) substitution. The enhancement in intensity, random variation of line width, and blue shift for highest frequency peak corresponding to A1g mode were observed. The ferric ion (Fe(3+)) concentration for different compositions determined from Raman spectral analysis agrees well with that deduced by means of X-ray diffraction line-intensity calculations and Mossbauer spectral analysis. An attempt was made to determine elastic and thermodynamic properties from Raman spectral analysis and elastic constants from cation distribution.

XRD, LPF and FTIR investigation of Mn-Bi alloy

High purity MnBi low temperature phase has been prepared and analyzed using X- ray diffraction, Lorentz-Polarization Factor and Fourier transforms infrared measurement. After synthesis of samples structural characterization has done on samples by X-ray diffraction, which shows that after making the bulk sample is in no single phase MnBi has been prepared by sintering Mn and Bi powder. The X-ray diffraction measurements were carried out using Bruker D8 Advance X-ray diffractometer. The X-rays were produced using a sealed tube and the wavelength of x-ray was 0.154nm (Cu K-alpha).and x-rays were detected using a fast counting detector based on Silicon strip technology (Bruker LynxEye detector). By Lorentz- Polarization Factor is affecting the relative intensity of diffraction lines on a powder form. The infrared absorption spectra of the alloys and intermetallic compound were measured at room temperature, in the wave number range 4000 to 400 cm−1 by a computerized spectrometer type Jasco FTIR-300 (JAPAN) using the KBr pellet technique. And by FTIR which shows absorption peaks of MnBi alloys.

Structural and Magnetic Studies on Chromium substituted Ni-Zn Nano Ferrite Synthesized by Citrate Gel Auto Combustion Method

Nano crystalline Ni0.5Zn0.5CrxFe2−xO4 particles with x varying from 0.00 to 0.25 in steps of 0.05 have been synthesized through citrate gel autocombustion method. When Ni0.5Zn0.5Fe2O4 nano particles were annealed at 1000 °C, the crystallite size increased while the lattice constant decreased slightly. For, the Cr3+ substituted samples annealed at 1000 °C, the variation in lattice constant, bondlengths, Me-Me distances and other structural parameters have been attributed to the dissimilarity in the ionic radius of the displaced (Fe3+) ion and the substituted (Cr3+) ion. Thermal studies indicated the autocombustion process which is an exothermic reaction between the nitrates salt solutions and the citric acid took place at about a temperature of 400 °C for Ni0.5Zn0.5Fe2O4. The M-H loops for all samples indicated a soft ferrite nature for all samples. The non-saturated hysteresis loop and high coercivity for the as prepared Ni0.5Zn0.5Fe2O4 nano particles has been attributed to the core-shell structure of the fine particles. When annealed at 1000 °C the saturation magnetization of Ni0.5Zn0.5Fe2O4 nano particles increased and attained the bulk value (70emu/gm). The specific saturation magnetization has been observed to decrease with increasing Cr3+ substitution and is ascribed to the reduction in the predominant A-B exchange interaction mechanism. By considering the site preferences cations a suitable distribution of the cations among the A & B-sites has been proposed for Ni0.5Zn0.5CrxFe2−xO4 nano particles annealed at 1000 °C and has been verified using the X-ray diffraction line intensity calculations. The FT-IR spectra of the annealed ferrite powders showed two significant absorption bands in the wave numbers around 400 cm−1 & 580 cm−1 and an additional shoulder at 360cm−1. The position and width of the bands have been observed to vary with Cr3+ substitution. The results of IR spectra are in support of the proposed cation distribution.

Assessing the life of boiler steel on the basis of anomalous thermal deformation of its crystal lattice

In vacuum thermocyclic tests, high-temperature X-ray diffraction patterns reveal anomalous thermal lattice deformation (λ-anomalies) of St10 (Ct10), 08H18N10T (08X18H10T), 12H1MF (12X1MФ), and Di-59 (ДИ-59) 10H13G12BS2N2TS2 (10X13Г12БC2H2Ц2) boiler steel within a narrow temperature range. That lattice deformation cannot be explained in terms of familiar phase transitions of types I and II and, according to analysis of the relative integral diffraction-line intensities, is associated with grain-boundary transformations and reorientation of the grains, with consequent modification of the physical and mechanical characteristics and the life of the heat-transfer surfaces.

Formation of nucleation centers for vortices in Bi-2223 superconducting core by dispersed Sn nanoparticles

Abstract In this study, we investigate the effect of the Sn diffusion at different annealing temperature in the range of 650–850 °C on the microstructural, electrical, mechanical and superconducting properties of the Bi 1.8 Pb 0.4 Sr 2.0 Ca 2.1 Cu 3.0 O y materials prepared by the standard solid state reaction method with the aid of bulk density, dc resistivity (ρ-T), transport critical current density ( J c ), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Vickers microhardness ( H v ) measurements. It is found that all the properties given above are significantly dependent upon both the Sn nanoparticles inserted in the Bi-2223 superconducting matrix and diffusion annealing temperature. Namely, the dc resistivity measurements indicate that all the samples exhibit the metallic behavior as a result of the electron–phonon interaction in the Bi-2223 crystal structure or logarithmic divergence in density of states at the Fermi level. Further, the normal state resistivity decreases with the enhancement of the annealing temperature owing to the increment of the metallic connection between the superconducting grains due to the optimization of the hole density and possible changes in the lattice vibration. Likewise, onset and offset critical transition temperature values tend to enhance with the diffusion annealing temperature, confirming not only the improvement of crystallinity and especially connectivity between the superconducting grains but the increment in the average grain size and mobile hole concentration in the Cu–O 2 slabs of the Bi-2223 system, as well. The decrement in the degree of the broadening stems from the degradation of the porosity, grain boundary resistivity and grain boundary weak-links in the system. Moreover, the results of J c show that the Sn inclusions (highly dispersed nanoparticles) form the effective flux pinning centers for the vortices in the crystal structure, and tightly bound to these nucleation centers. Thus, the J c value steeply increases from 852 A cm −2 to 4307 A cm −2 with the diffusion annealing temperature. Similar findings are valid for the microstructural characteristics obtained from the SEM images belonging to the samples. The annealing temperature of 850 °C develops considerably the surface morphology and interaction between the superconducting grains. Hence, the sample annealed at 850 °C for 24 h exhibits the smoothest and densest surface morphology. Similarly, the bulk density analysis illustrates that the densities regularly rise from 5.582 to 6.102 g/cm 3 with increasing the annealing temperature, confirming that more and more Sn inclusions penetrate into the superconducting grains or over grain boundaries in the crystal structure. This is associated with the enhancement of the connectivity (interaction) between the superconducting grains. At the same time, the results of the XRD experiments display that all the samples composed of two superconducting phases (Bi-2223 and Bi-2212) present the polycrystalline superconducting phases but in different intensity of diffraction lines. With increasing the annealing temperature up to 850 °C, the intensity of diffraction lines belonging to the high- T c phase (Bi-2223) becomes stronger and so the best superconducting properties are observed for the sample prepared at the annealing ambient of 850 °C for 24 h, being even favored by the largest (lowest) cell parameter c ( a ). Furthermore, Vickers microhardness measurements conducted at different applied indentation test load (0.245 N ⩽ F ⩽ 2.940 N) demonstrate that all the Bi-2223 ceramics obey the typical Indentation Size Effect (ISE) behavior, and the mechanical properties increase with the diffusion annealing temperature. The long and short of it is that the Sn inclusions and especially diffusion annealing temperature up to 850 °C are favorable for the formation velocity of Bi-2223 phase.

Crystal Defects and Cation Redistribution Study on Nanocrystalline Cobalt-Ferri-Chromites by Positron Annihilation Spectroscopy

Positron lifetime and Doppler broadening measurements were carried out on nanocrystalline (grain size ~60–65 nm) samples of the Cr3+-substituted cobalt ferrite system with general chemical formula CoCrxFe2−xO4 (x=0.0−2.0) synthesized by the coprecipitation technique. The results indicated selective trapping of positrons in large vacancy clusters initially at the tetrahedral (A-) sites and then with Cr3+-substitution up to concentration (x)=0.7, at the octahedral (B-) sites. The results are consistent with the cation distribution determined from X-ray diffraction line intensity calculations, which indicated partial inversion of the inverse spinel ferrite, subsequent stabilization over a range of substitution (x=0.7 to 1.7), and finally the full inversion to the normal spinel chromite (CoCr2O4, x=2.0). In the intermediate range of substitution, lattice contraction prevented a fraction of Co2+ ions released from the (B-) sites from entering the tetrahedral sites, and these vacancies at the (A-) sites trapped positrons. Although the samples were composed of nanocrystalline grains, only an insignificant fraction of positrons were diffused and annihilated at the grain surfaces, since the grain sizes and the thermal diffusion length of positrons nearly overlapped.

Sn diffusion coefficient and activation energy determined by way of XRD measurement and evaluation of micromechanical properties of Sn diffused YBa2Cu3O7−x superconducting ceramics

This study manifests not only the effect of Sn diffusion on physical, electrical, mechanical, structural and superconducting properties of the bulk YBa2Cu3O7−x (Y123) superconductors prepared by the conventional solid-state reaction route by use of electrical resistance, X-ray diffraction analysis (XRD), electron dispersive X-ray, scanning electron microscopy, transport critical current density (J c ) and Vickers microhardness (H v ) measurements but also the diffusion coefficient and the activation energy of tin (Sn) in the Y123 material for the first time. The diffusion coefficient and the activation energy of Sn are investigated in the temperature range 500–945 °C using the change of the lattice parameters extracted from the XRD patterns. The resistance (at room temperature), critical (onset and offset) temperature, variation of critical temperature, hole-carrier concentration, crystallinity, lattice parameter, texturing, surface morphology, lotgering index, element distribution, critical current density, oxygen content, load dependent microhardness, elastic modulus and yield strength values are obtained for the pure and Sn diffused samples and compared with each other. One can see that all superconducting parameters given above depend sensitively on the Sn diffusion on Y123 system. The obtained results exhibit that the room temperature resistance enhances with the Sn diffusion because of the hole filling when the onset \( (T_{c}^{onset} ) \) and offset \( (T_{c}^{offset} ) \) critical temperatures are obtained to be about 93.4 and 89.6 K for the pure sample as against 92.2 and 88.1 K for the Sn diffused sample, respectively. This may be attributed to the fact that the decrement in the critical temperatures is due to the deterioration of crystallinity and descend in the grain size. As for the critical current density measurements, J c values are obtained to be about 125.4–65.3 A/cm2, respectively, for the undiffused and Sn diffused materials. This may be led to the decrease of the flux pinning mechanism stemming from the stacking faults, planar and micro-defects. At the same time, XRD measurements display that the samples produced in this work exhibit the polycrystalline superconducting phase with the changing intensity of diffraction lines. Besides, the peak intensities belonging to major phase (Y123) decrease monotonously with Sn diffusion in the system; however, new peaks belonging to the minor (BaCuO2) phases start to appear for Sn diffused sample confirming both the reduction of the grain size and degradation of the critical temperature. Moreover, the pure sample is confirmed by both enhancement of a and b lattice constants and the decrement of the cell parameter c of the sample in comparison with that of the Sn diffused sample. According to SEM examination, the crystallinity and grain connectivity suppress with the Sn diffusion. EDX measurements illustrate that not only do the elements used for the preparation of the Y123 superconductors with and without Sn diffusion distribute homogeneously but also the level of Cu element reduces with the Sn diffusion, presenting that the Cu2+ ions may partly be diffused by tetravalent tin (Sn4+) ions. Further, surprising results of the Vickers microhardness values demonstrate that the pure sample visualizes Indentation Size Effect (ISE) feature; however, the Sn diffused sample reports Reverse Indentation Size Effect (RISE) nature. Additionally, the diffusion coefficient is observed to increase from 1.11 × 10−9 to 2.82 × 10−8 cm2 s−1 as the diffusion-annealing temperature increases, verifying that the Sn diffusion at lower temperatures is much less significant as compared to the higher ones. Temperature dependence of the Sn diffusion coefficient and activation energy in the range of 500–945 °C is defined with the aid of the following equation: \( D = 7.78 \times 10^{ - 6} { \exp }\left[ {\left( {( - 0.590 \pm 0.005){\raise0.7ex\hbox{${\text{eV}}$} \!\mathord{\left/ {\vphantom {{\text{eV}} {k_{B} T}}}\right.\kern-0pt} \!\lower0.7ex\hbox{${k_{B} T}$}}} \right)} \right] \).

Effect of the size factor on the lattice parameter and the Debye temperature of iron alloys doped with chromium or vanadium

For modelling thermodynamic properties of the Fe-Cr alloys necessary to know the concentration dependences of the Debye temperature, the lattice parameter, the elastic moduli, the average magnetic moment, and the Curie temperature. The investigations are performed on iron alloys with chromium or vanadium in the concentration range 2–8 at %. The lattice parameters of the alloys are determined by comparing them with a standard sample placed on the surface of the sample under study. As the standard, a silicon crystal is used, and its lattice parameter is measured by the high-precision Bond method. The Debye temperatures of the alloys are determined from the temperature dependences of the integrated X-ray diffraction line intensities. The specific magnetization is measured by the Faraday method to compare the magnetic properties of Fe-Cr and Fe-V alloys. The partial magnetic moment of the iron atom is shown to increase with the alloying-element concentration.