scholarly journals Software Package Application for Self-consistent Processing of X-ray Measurement Data for Studying Structural Properties and Parameters of Objects

The article presents the results of TiN diffusion-barrier layers studies on a silicon substrate, carried out with the use of the copyrighted software package. In this paper, it is proposed to use several methods for studying the structures and combine them in the form of an integrated approach, which allows not only to increase the calculation accuracy but also to solve most of the arisen problems. Based on this approach, an automated software package for X-ray spectral and X-ray structural analysis was developed to study the elemental and phase composition of the objects, including the analysis of ore minerals, which allows not only to obtain a more complete and detailed picture of the studied objects, but also to increase the sensitivity threshold detection of individual elements that are not detected by individual methods of analysis.

2018 ◽  
Vol 83 (03) ◽  
pp. 419-426 ◽  
Author(s):  
Degao Zhai ◽  
Luca Bindi ◽  
Panagiotis C. Voudouris ◽  
Jiajun Liu ◽  
Stylianos F. Tombros ◽  
...  

AbstractDuring a study of the ore minerals belonging to the recently discovered Shuangjianzishan Ag–Pb–Zn deposit in NE China, we have discovered exceptional selenium enrichment in canfieldite (up to 11.6 wt.% of Se). Incorporation of Se into canfieldite has been investigated by an integrated approach using field emission scanning electron microscopy, electron microprobe and single-crystal X-ray diffraction. Canfieldite has been identified as one of the dominant Ag-bearing ore minerals in the studied deposit, which occurs mostly in slate-hosted vein type Ag–Pb–Zn ore bodies. Selenium is either homogeneously or, remarkably, heterogeneously distributed in the different canfieldite fragments studied. Chemical variations of Se are mostly attributable to a series of retrograde reactions resulting in diverse decomposition and exsolution of primary phases during cooling, or alternatively, related to influxes of Se-rich fluids during the formation of canfieldite. To evaluate the effects of the Se-for-S substitution in the structure, a crystal of Se-rich canfieldite [Ag7.98Sn1.02(S4.19Se1.81)Σ6.00] was investigated. The unit-cell parameters are: a = 10.8145(8) Å and V = 1264.8(3) Å3. The structure was refined in the space group F$\bar{4}$3m to R1 = 0.0315 for 194 independent reflections, with 20 parameters. The crystal structure of Se-rich canfieldite was found to be topologically identical to that of pure canfieldite. If the short Ag–Ag contacts are ignored (due to the disorder), the two Ag atoms in the structure can be considered as three-fold (Ag1) and four-fold (Ag2) coordinated. Tin adopts a regular tetrahedral coordination. As in the case of Te-rich canfieldite, the refinement of the site-occupancy factor indicates that Se is disordered over the three anion positions.


Author(s):  
G.F. Bastin ◽  
H.J.M. Heijligers ◽  
J.M. Dijkstra

For the calculation of X-ray intensities emitted by elements present in multi-layer systems it is vital to have an accurate knowledge of the x-ray ionization vs. mass-depth (ϕ(ρz)) curves as a function of accelerating voltage and atomic number of films and substrate. Once this knowledge is available the way is open to the analysis of thin films in which both the thicknesses as well as the compositions can usually be determined simultaneously.Our bulk matrix correction “PROZA” with its proven excellent performance for a wide variety of applications (e.g., ultra-light element analysis, extremes in accelerating voltage) has been used as the basis for the development of the software package discussed here. The PROZA program is based on our own modifications of the surface-centred Gaussian ϕ(ρz) model, originally introduced by Packwood and Brown. For its extension towards thin film applications it is required to know how the 4 Gaussian parameters α, β, γ and ϕ(o) for each element in each of the films are affected by the film thickness and the presence of other layers and the substrate.


2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Ibrahim Shaik ◽  
S. K. Begum ◽  
P. V. Nagamani ◽  
Narayan Kayet

AbstractThe study demonstrates a methodology for mapping various hematite ore classes based on their reflectance and absorption spectra, using Hyperion satellite imagery. Substantial validation is carried out, using the spectral feature fitting technique, with the field spectra measured over the Bailadila hill range in Chhattisgarh State in India. The results of the study showed a good correlation between the concentration of iron oxide with the depth of the near-infrared absorption feature (R2 = 0.843) and the width of the near-infrared absorption feature (R2 = 0.812) through different empirical models, with a root-mean-square error (RMSE) between < 0.317 and < 0.409. The overall accuracy of the study is 88.2% with a Kappa coefficient value of 0.81. Geochemical analysis and X-ray fluorescence (XRF) of field ore samples are performed to ensure different classes of hematite ore minerals. Results showed a high content of Fe > 60 wt% in most of the hematite ore samples, except banded hematite quartzite (BHQ) (< 47 wt%).


Author(s):  
G. Grigorenko ◽  
A. Borisova

Abstract An integrated approach was developed for investigation of thermal spray coatings with the amorphous-crystalline structure. The new approach combines methods of metallography, differential thermal and X-ray phase analysis, scanning electron microscopy and X-ray microanalysis. This makes it possible to reveal structural, phase and chemical heterogeneity, determine the degree of amorphization of coatings, temperature and heat of crystallization of the amorphous phase during heating. The new integrated approach was used to study amorphous-crystalline coatings of the Ni-P, Fe-Ni-B and Fe-B systems produced by thermal spraying.


1998 ◽  
Vol 5 (5) ◽  
pp. 1287-1297 ◽  
Author(s):  
Daniel Aberdam

A software package for extended X-ray absorption fine structure (EXAFS) data extraction and modelling, running on DOS- or Windows-operated PCs, is described. This package is written with the aim of giving the user a tool to undertake all steps of data processing and modelling, rather than making use of the most recent programming facilities. However, it remains easy to use, and self-explanatory to those who have already worked with EXAFS. It is divided into two main executable pieces of software. The first one is used to extract the EXAFS k n χ(k) function from the data and isolate the shell contributions by Fourier filtering. A tool to sum the spectra before EXAFS extraction is provided. The second one is designed to model the EXAFS spectra or the shell contributions, using amplitude and phase data either from McKale's tables, computed from the FEFF program or extracted from experimental reference spectra. This modelling program allows either an optimization of the simulation by a least-mean-square gradient algorithm, with a statistical evaluation of the result of optimization, or, in the case of a single shell, a direct determination of the four main parameters (neighbour distance and number, energy shift and Debye–Waller factor) by decorrelation of the phase and amplitude. In the presence of anharmonicity, the cumulant expansion of the radial distribution of distances is obtained from the phase and amplitude decorrelation. This package is in use at the Collaborative Research Group on Interfaces (CRG-IF) bending-magnet #32 X-ray line (BM-32) at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France.


2020 ◽  
Author(s):  
Alessio Bartocci ◽  
florence szczepaniak ◽  
Tao Jiang ◽  
Natacha Gillet ◽  
Elise Dumont

Here, we propose a molecular dynamics investigation of the supramolecular association of sulfonatedcalix-[8]-arenes to cytochrome c. The binding sites prone to interactions with sulfonated calixarenescan be identified without prior knowledge of the X-ray structure, and the binding free energiesestimated by molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) post-analysis arefound to be in neat agreement with the isothermal titration calorimetry (ITC) measurements The per-residuedecomposition reveals the detailed picture of this electrostatically-driven association and notably therole of the arginine R13 as a bridge residue between the two main anchoring sites. In addition,the analysis of the residue behavior by means of a supervised machine learning protocol unveils the formation of an hydrogen bond network far from the binding sites, increasing the rigidity of theprotein.


2021 ◽  
Author(s):  
Dino Zivojevic ◽  
Muhamed Delalic ◽  
Darijo Raca ◽  
Dejan Vukobratovic ◽  
Mirsad Cosovic

The purpose of a state estimation (SE) algorithm is to estimate the values of the state variables considering the available set of measurements. The centralised SE becomes impractical for large-scale systems, particularly if the measurements are spatially distributed across wide geographical areas. Dividing the large-scale systems into clusters (\ie subsystems) and distributing the computation across clusters, solves the constraints of centralised based approach. In such scenarios, using distributed SE methods brings numerous advantages over the centralised ones. In this paper, we propose a novel distributed approach to solve the linear SE model by combining local solutions obtained by applying weighted least-squares (WLS) of the given subsystems with the Gaussian belief propagation (GBP) algorithm. The proposed algorithm is based on the factor graph operating without a central coordinator, where subsystems exchange only ``beliefs", thus preserving privacy of the measurement data and state variables. Further, we propose an approach to speed-up evaluation of the local solution upon arrival of a new information to the subsystem. Finally, the proposed algorithm provides results that reach accuracy of the centralised WLS solution in a few iterations, and outperforms vanilla GBP algorithm with respect to its convergence properties.


2010 ◽  
Vol 43 (4) ◽  
pp. 929-936 ◽  
Author(s):  
David Babonneau

A software package for performing modelling and analysis of GISAXS (grazing-incidence small-angle X-ray scattering) data within the distorted-wave Born approximation has been developed using the IGOR Pro scripting language (http://www.wavemetrics.com). The tool suite uses a slab-model approach with the Abélès matrix method to calculate X-ray reflectivity curves, electric field intensity distributions and GISAXS intensities from supported or buried scatterers arranged in two or three dimensions in a stratified medium. Models are included to calculate the scattered intensity for monodisperse, polydisperse and interacting particles with various size distributions, form factors and structure factors. The source code for the entire package is freely available, allowing anyone to develop additional tools.


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