X-ray Diffraction Peak Intensity Research Articles

Simultaneous determination of tensile and shear strains of crystalline bilayers using three Bragg reflections of X-rays

A method for the simultaneous determination of nine strain coefficients, both shear and tensile, of crystalline bilayers is proposed and realized. The X-ray diffraction peak intensities along 2θ (vertical) and β (horizontal) scans relative to the plane of incidence of three Bragg reflections whose atomic planes are not parallel to each other can be used to obtain shear and tensile strain coefficients. The theoretical considerations and experimental examples for single-crystal GeSi/Si overlayers are reported. It is also demonstrated that, for GeSi/Si, the shear and tensile strain coefficients of the Si substrate tend to vanish when the GeSi layer is thicker than 40 nm.

Magnetic Resonance Investigations of h-YbMnO3

Polycrystalline samples of ytterbium manganites have been synthesized with deficiency of Yb3+ ions. The X-ray analysis showed that the structure of the sample is hexagonal (h-YbMnO3) with the space group P63cm. The analysis of the X-ray diffraction peak intensities allowed to find the occupancy of Yb3+ and Mn3+ positions which are about 89 and 100 %, respectively. The electron spin resonance (ESR) measurements were performed using X (9.4 GHz), Q (34.2 GHz) and W (94.1 GHz) bands. The ESR spectrum displays the broad exchange-narrowed Mn3+ resonance line and an additional signal, which is attributed to the ferromagnetically correlated clusters, formed by mixed-valence manganese ions near vacant Yb3+ positions, confirmed by the observation of the hysteresis loop in the magnetization of h-YbMnO3.

On the role of secondary extinction in the measurement of the integrated intensity of X-ray diffraction peaks and in the determination of the thickness of damaged epitaxial layers

The integrated intensity of X-ray diffraction reflections has been measured for a series of epitaxial layers of AIII nitrides (GaN, AlN, AlGaN) grown on different substrates (sapphire, SiC) and characterized by different degrees of structural perfection. It has been shown that, despite a high density of dislocations and a significant broadening of the diffraction peaks, the obtained values are not described by the kinematic theory of X-ray diffraction and suggest the existence of extinction. The results have been analyzed on the basis of the Darwin and Zachariasen extinction models. The secondary extinction coefficients and the thicknesses of epitaxial layers have been determined using two orders of reflection both in the Bragg geometry (0002 and 0004) and in the Laue geometry (\(10\bar 10\)) and \(10\bar 20\)). It has been demonstrated that the secondary extinction coefficient is the greater, the smaller is the broadening of the diffraction peaks and, consequently, the dislocation density. It has been found that, for epitaxial layers with a regular system of threading dislocations, the secondary extinction coefficient for the Laue reflections is substantially greater than that for the Bragg reflections.

Disruption of crystalline structure of Sn3.5Ag induced by electric current

This study presented the disruption of the Sn and Ag3Sn lattice structures of Sn3.5Ag solder induced by electric current at 5–7 × 103 A/cm2 with a high resolution transmission electron microscope investigation and electron diffraction analysis. The electric current stressing induced a high degree of strain on the alloy, as estimated from the X-ray diffraction (XRD) peak shift of the current stressed specimen. The XRD peak intensity of the Sn matrix and the Ag3Sn intermetallic compound diminished to nearly undetectable after 2 h of current stressing. The electric current stressing gave rise to a high dislocation density of up to 1017/m2. The grain morphology of the Sn matrix became invisible after prolonged current stressing as a result of the coalescence of dislocations.

Preparation of CuAlO2Thin Films by Sol-Gel Method Using Nitrate Solution Dip-Coating

CuAlO 2 thin films are prepared by sol-gel dip-coating followed by annealing in nitrogen atmosphere using copper nitrate and aluminum nitrate as metal source materials. X-ray diffraction (XRD) patterns show (003), (006) and (009) oriented peaks of CuAlO 2 at annealing temperature of 800 – 1000°C. This result indicates that the CuAlO 2 films prepared in the present work are c -axis oriented. XRD peak intensity increase with annealing temperature and becomes maximum at 850°C. The CuAlO 2 XRD peak decreased at annealing temperature of 900°C with appearance of a peak of CuO, and then increased again with annealing temperature until 1000 °C. The films have bandgap of 3.4 eV at annealing temperature of 850°C in which the transparency becomes the highest. At the annealing temperature of 850°C, scanning electron microscope (SEM) observation reveals that the films are consist of amorphous fraction and microcrystalline CuAlO 2 fraction.

Evaluation of electrical and optical characteristics of ZnO/CdS/CIS thin film solar cell

In this study, device modeling and simulation are conducted to explain the effects of each layer thickness and temperature on the performance of ZnO/CdS/CIS thin film solar cells. Also, the thicknesses of the CIS and CdS absorber layers are considered in this work theoretically and experimentally. The calculations of solar cell performances are based on the solutions of the well-known three coupling equations: the continuity equation for holes and electrons and the Poisson equation. Our simulated results show that the efficiency increases by reducing the CdS thickness. Increasing the CIS thickness can increase the efficiency but it needs more materials. The efficiency is more than 19% for a CIS layer with a thickness of 2 μm. CIS nanoparticles are prepared via the polyol route and purified through centrifugation and precipitation processes. Then nanoparticles are dispersed to obtain stable inks that could be directly used for thin-film deposition via spin coating. We also obtain x-ray diffraction (XRD) peak intensities and absorption spectra for CIS experimentally. Finally, absorption spectra for the CdS window layer in several deposition times are investigated experimentally.

Enhanced model for determining the number of graphene layers and their distribution from X-ray diffraction data.

A model consisting of an equation that includes graphene thickness distribution is used to calculate theoretical 002 X-ray diffraction (XRD) peak intensities. An analysis was performed upon graphene samples produced by two different electrochemical procedures: electrolysis in aqueous electrolyte and electrolysis in molten salts, both using a nonstationary current regime. Herein, the model is enhanced by a partitioning of the corresponding 2θ interval, resulting in significantly improved accuracy of the results. The model curves obtained exhibit excellent fitting to the XRD intensities curves of the studied graphene samples. The employed equation parameters make it possible to calculate the j-layer graphene region coverage of the graphene samples, and hence the number of graphene layers. The results of the thorough analysis are in agreement with the calculated number of graphene layers from Raman spectra C-peak position values and indicate that the graphene samples studied are few-layered.

Synthesis and characterization of hierarchical nanoporous HY zeolites from acid-activated kaolin

Hierarchical nanoporous HY zeolites were synthesized from acid-activated kaolin. The hierarchical factor (HF) was maximized by varying the aging and crystallization time. This was achieved by maximizing the external surface area without greatly reducing the micropore volume. The resulting products were characterized using X-ray diffraction (XRD), X-ray fluorescence, N2 adsorption, and NH3 temperature-programmed desorption. The nanoporous HY zeolite with the highest HF was obtained by aging for 48 h and a crystallization time of 24 h. The acidity and crystallinity varied depending on the operating parameters. Incorporation of an appropriate amount of NaCl was also vital in maximizing the HF, crystallinity, and acidity. The sample crystallinities were determined by comparing their XRD peak intensities with those of a conventional Y zeolite. The results show that optimizing this process could lead to a widely acceptable commercial route for HY zeolite production.

Erratum: Effects of Zn amount on the properties of Zn-Cu2O composite films grown for PEC photoelectrodes by using electrochemical deposition

In this study, Zn-Cu2O composite films were grown on fluorine-doped tin-oxide (FTO) substrates by using the electrochemical deposition method. Various amounts of Zinc (Zn) were added to grow the Zn-Cu2O composite films. We analyzed the morphological, structural, optical energy band gap and photocurrent density properties of the Zn-Cu2O composite films by using various measurements such as field-emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), UV-visible spectrophotometry and potentiostat/galvanostat measurements, respectively. As a result, the highest photocurrent density value of −4.04 mA/cm2 was obtained for the 30-wt% sample, which had the lowest Cu2O (111)/ ZnO (101) XRD peak intensity ratio. The highest photocurrent density value from the 30-wt% sample was approximately 2.35 times higher than that from the non-composite Cu2O film (0-wt% sample). From this study, we found that adding Zn could improve the photocurrent values of Zn-Cu2O composite films.

The Study of Surface Properties of Tokamak First Wall Using TiN Coated on Stainless Steel

Structural properties of the synthesized TiN thin film on 316L stainless steel (S.S.316L) were studied to determine its potential application as a protective layer for first wall of Tokamaks. For this purpose we deposited TiN on stainless steel 316L (TiN/S.S.316L) via DC magnetron sputtering method and annealing at 700 °C. Before and after exposure, samples were analyzed by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and a spectrophotometer. The XRD analysis for studying crystalline structure of samples shows the position and intensity of XRD peaks has changed after exposing to 500 shots of Tokamak. It was found that the S.S.316L sample was severely damaged, its reflection dropped significantly but the SEM images show that plasma exposure has not created any cracks and lines on the surface of the TiN/S.S.316L sample and mass of dust particle has been assembled in some area of the sample.

Determination of transition metal ion distribution in cubic spinel Co1.5Fe1.5O4 using anomalous x-ray diffraction

We report anomalous x-ray diffraction studies on Co ferrite with composition Co1.5Fe1.5O4 to obtain the distribution of transition metal ions in tetrahedral and octahedral sites. We synthesize spinel oxide (Co1.5Fe1.5O4) through co-precipitation and subsequent annealing route. The imaginary part (absorption) of the energy dependent anomalous form factor is measured and the real part is calculated theoretically through Kramers–Krönig transformation to analyze anomalous x-ray diffraction peak intensities. Fe and Co K-edge x-ray absorption near edge structure (XANES) spectra are used to estimate charge states of transition metals. Our analysis, within experimental errors, suggests 44% of the tetrahedral sites contain Co in +2 oxidation state and the rest 56% sites contain Fe in +2 and +3 oxidation states. Similarly, 47% of the octahedral sites contain Fe in +3 oxidation states, whereas, the rest of the sites contain Co in +2 and +3 oxidation states. While a distinct pre-edge feature in the Fe K-edge XANES is observed, Co pre-edge remains featureless. Implications of these results to magnetism are briefly discussed.

Effects of Deposition Inclination Angle on Microstructure and Electrical Properties of Al-Doped ZnO Coating Films

A flat plate in the deposition stage is designed to be tilted flexibly to form an inclination angle (θ) between an ion beam and the direction normal to a polyethylene terephthalate (PET) substrate. Five kinds of PET/aluminum-doped zinc oxide specimens were prepared to examine the effects of inclination angle on the microstructures, crystals, chemical compositions, and electrical properties. An increase in the inclination angle results in X-ray diffraction peak intensity variations in ZnO and a reduction in the composite d-spacing. As the measure of the oxygen vacancies, the O2-peak intensity ratio (IRO2) obtained using the X-ray photoelectron spectrometry (XPS) is evaluated. The IRO2 value increased with increasing the inclination angle, and it is proportional to the porosity integration over the visible light wavelengths. An increase in IRO2 is favorable for the reduction in composite grain size (gComposite). A smaller composite grain size (gComposite) of ZnO particles and a larger energy gap (Eg) can be obtained from applications of nonzero inclination angle. An appropriate nonzero inclination angle increases hardness and reduced elastic modulus and decreases the carrier concentration and carrier mobility of the specimen significantly.

Effects of curing temperature on physical properties of hydrothermally-grown yttrium-doped ZnO nanorods

We investigated the effects of the curing temperature on physical properties of hydrothermal synthesized yttrium-doped ZnO (YZO) nanorods. Compared to the as-grown sample, the c-axis preference (i.e., the peak intensity of x-ray diffraction at the (002) Bragg angle) was much enhanced after curing in vacuum at 200 °C. In addition, 200-°C-cured YZO nanorods showed a significant decrease in the number of metastable oxygen bonds. These resulted in both the increase in ultra-violet emission and the decrease in oxygen-related deep-level emission.

Structure–property relationship in NaCa4B5O17 (B = Nb, Ta) perovskites

The crystal structure of NaCa4B5O17 (B = Nb, Ta) ceramics sintered at 1,200–1,350 °C was investigated. Analysis of X-ray diffraction (XRD) data revealed that both the NaCa4Nb5O17 and NaCa4Ta5O17 compounds crystallized into the monoclinic (P21/b) symmetry. The observed variation in the XRD peak intensities of NaCa4Nb5O17 with sintering temperature might be associated with the preferred orientation of grains rather than the change in crystal symmetry. Microstructural examination revealed a visible increase in grain size and change in grain morphology with increasing sintering temperature. The presence of the same active modes on the Raman spectra of samples sintered at 1,200–1,350 °C did not indicate any change in crystal symmetry with temperature. NaCa4Ta5O17 exhibited relative permittivity er ~ 41, quality factor Q × f o ~ 11,595 GHz and temperature coefficient of resonance frequency τf ~ −13.9 ppm/°C.

Physical and Structural Characterization of Biofield Energy Treated Carbazole

Carbazole is a class of phytochemical associated with cancer prevention. It attracted a significant interest in recent time for their usefulness in synthetic heterocyclic chemistry, analytical chemistry and pharmacology. The aim of the study was to evaluate the impact of biofield energy treatment on carbazole by various analytical methods. The study was performed in two groups i.e. control and treatment. The treatment group was subjected to Mr. Trivedi’s biofield treatment. Subsequently, both the samples were characterized with respect to physical and structural properties using X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), gas chromatography-mass spectrometry (GC-MS), laser particle size analyzer, and surface area analyzer. The XRD study revealed that the crystallite size of treated carbazole was decreased significantly with 37.5% as compared to the control. In addition, the intensity of XRD peaks was slightly decreased as compared to the control. The latent heat of fusion (ΔH) of treated carbazole was substantially increased by 253.6% as compared to the control. Maximum degradation temperature (Tmax) of treated carbazole was increased by 41.46°C as compared to the control (211.93°C to 253.39°C). FT-IR spectra showed similar stretching frequencies in both control and treated carbazole samples. GC-MS data revealed that isotopic abundance ratio of either 13C/12C or 15N/14N or 2H/1H (PM+1/PM) of treated carbazole was significantly increased up to 278.59%. Particle size analysis showed substantial decrease in average particle size (d50) and d90 of the treated carbazole by 25.24% and 4.31%, respectively as compared to the control. The surface area analysis exhibited an increase in the surface area of treated sample by 4.8% as compared to the control. Overall, the experimental results suggest that biofield energy treatment has significant effect on physical, spectral and thermal properties of carbazole.

Physicochemical and Spectroscopic Characteristics of Biofield Treated <i>p</i>-Chlorobenzophenone

<i>p</i>-Chlorobenzophenone (<i>p</i>-CBP) is the important chemical intermediate used for the synthesis of several pharmaceutical drugs like fenofibrate, cetirizine, alprazolam, and benzodiazepine. The aim of this study was set to evaluate the impact of biofield energy treatment on physicochemical and spectroscopic properties of <i>p</i>-CBP. The study was accomplished in two groups <i>i.e.</i> control and treated. The treated group was subjected to Mr. Trivedi’s biofield energy treatment. Subsequently, the control and treated samples of <i>p</i>-CBP were analyzed using X-ray diffraction (XRD), particle size analyzer, surface area analyzer, differential scanning calorimetry (DSC), thermogravimetric analysis-derivative thermogravimetric analysis (TGA-DTG), Fourier transform infrared (FT-IR), and ultraviolet-visible (UV-Vis) spectroscopy. The XRD study exhibited the increase in average crystallite size (25.93%) as well as the intensity of XRD peaks of treated <i>p</i>-CBP, as compared to the control. The particle size analysis showed the reduction in particle size of fine particles (≤51.49 µm) by 21.6% (d₁₀), whereas, increase in particle size of large particles (≥433.59 µm) by 12.82% (d₉₀) and 17.71% (d₉₉), respectively after biofield treatment, as compared to the control. The surface area analysis exhibited the surface area as 0.7005 m²/g in control and 0.7020 m²/g in treated sample of <i>p</i>-CBP. The DSC thermogram of treated <i>p</i>-CBP exhibited the slight decrease in melting temperature. However, the latent heat of fusion was significantly altered (24.90%) after biofield energy treatment as compared to the control. TGA analysis showed the weight loss by 57.36% in control and 58.51% in treated sample. In addition, the onset temperature of thermal degradation was also decreased by 6.32% after biofield energy treatment as compared to the control <i>p</i>-CBP. The FT-IR and UV spectroscopic study did not show the alteration in the wavenumber and wavelength, respectively in treated <i>p</i>-CBP as compared to the control. Altogether, the XRD, particle size and thermal analysis suggest that biofield energy treatment has significant impact on physical and thermal properties of treated <i>p</i>-CBP.

Characterization of Physical, Thermal and Spectral Properties of Biofield Treated Date Palm Callus Initiation Medium

The date palm is mainly cultivated for the production of sweet fruit. Date palm callus initiation medium (DPCIM) is used for plant tissue culture applications. The present work is intended to evaluate the impact of Mr. Trivedi’s biofield energy treatment on physical, thermal and spectral properties of the DPCIM. The control and treated DPCIM were evaluated by various analytical techniques such as X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, particle size analyzer (PSA), surface area analyzer and ultra violet-visible spectroscopy (UV-vis) analysis. The XRD analysis revealed a decrease in intensity of XRD peaks of the treated sample as compared to the control. The crystallite size of the treated DPCIM (81.02 nm) was decreased with respect to the control sample (84.99 nm). The DSC analysis showed a slight decrease in melting temperature of the treated sample. Additionally, the latent heat of fusion of treated sample was changed by 45.66% as compared to the control sample. The TGA analysis showed an increase in onset degradation temperature of the treated sample (182oC) as compared to the control sample (142oC). This indicated the increase in thermal stability of the treated DPCIM. PSA results demonstrated an increase in average particle size (d50) and size showed by 99% of particles (d99) by 19.2 and 40.4%, respectively as compared to the control sample. The surface area analyzer showed a decrease in surface area of treated DPCIM by 13.4%, which was well supported by the particle size results. UV spectra of the treated sample showed the disappearance of absorption peak 261 nm in treated sample as compared to the control. Overall, the result showed that biofield energy treatment has a paramount influence on physical, thermal and spectral properties of DPCIM. Therefore, it is assumed that biofield treated DPCIM could be used as a better medium for plant tissue culture applications.

Effects of Milling Conditions on Nano-scale MnFe(P,Si) Particles by Surfactant-assisted High-energy Ball Milling

The influence of the milling conditions on the nano-scale MnFe(P,Si) particles obtained by surfactant-assisted high-energy ball milling has been investigated by X-ray diffraction (XRD) and magnetic measurements. The presence of surfactant oleic acid prevents the re-welding of crushed particles and enhances the dispersion of nanoparticles in the solvent during the ball milling. The XRD peak intensities decrease and the peaks broaden with increasing milling time, indicating a decrease in grain size. For increasing milling time, the spontaneous magnetization becomes lower and the thermal hysteresis becomes smaller. The surfactant concentration does not have a strong impact on the magnetic properties of the obtained nanoparticles, which is consistent with the X-ray diffraction data showing the same patterns at different surfactant concentrations.

Preparation and Characterization of Tourmaline/ZnO Composite Thin Films by a Facile Wet-Chemical Route

A series of tourmaline/ZnO composite thin films were prepared by the facile route of low-temperature wet chemical method. X-ray diffraction (XRD) and Raman Spectroscopy analyses showed the hybrid spectroscopic characters of tourmaline and ZnO. With adding the different amount of tourmaline powder, ZnO tended to exhibit the different peak intensity of X-ray diffraction and Raman vibration. ZnO deposited into bending nanosheets and intersected to upstanding nanostucture on the surface of tourmaline particles in SEM images. The optical adsorption properities obtained by the UV-Vis spectra indicated that the addition of tourmaline had enhanced the maximum absorption strength, and had shifted the absorption wavelength and the absorption range of ZnO crystals.

EFFECTS OF MILLING TIME ON MAGNETIC PROPERTIES OF Ni-C COMPOSITES

EFFECTS OF MILLING TIME ON MAGNETIC PROPERTIES OF Ni-C COMPOSITES. A study on the effect of milling time to magnetic properties of Ni-C composites has been carried out. The composite materials of Ni-C was prepared by mixing nickel and carbon (C) powders with the weight ratio of Ni and C is 2% : 98%, and by varying the milling time for 25, 50 and 75 hours using High Energy Milling (HEM) technique. Results of identification by X-ray diffractometer (XRD) showed that X-ray diffraction peak intensity decreased and particle size was going smaller with the increasing of milling time. Whereas the optimal milling time for Ni-C composite system is 50 hours. This is indicated by the largest surface area (about 483 m2/g) and highest magnetic properties of Ni-C compared with other milling time. The results of magnetic parameter value for milling time of 50 hours shows the highest values of Ms (Saturated Magnetization), Mr (Remanence Magnetization) and Hc (Coercive Field) i.e. 2.29 emu/g, 0.43 emu/g and 0.017 Tesla, respectively. The highest value of magnetoresistance ratio (MR) i.e. 14.22% at 7.5 kOe magnetic field was also reached. Keywords : Ni-C Composites, Milling Technique, Magnetic Parameters, Magnetoresistance Ratio.