arXiv subjects

Noureddine Hadji

Publications and source records attributed to Noureddine Hadji.

3 recordsLinked to original sources

arXiv2021

Expressions and Formulas to Expand and Add Potentiality to Knowledge Underlying Diffraction

Development generating diffraction-related valuable expressions and formulas capable of initiating new era for diffraction and for scientific domains that use it provided. The main expression, among these, gives diffracted intensity as explicit function of true and absolute distribution of interatomic vectors (DIV) and is suitable for constructing analytical techniques capable of converting experimental diffraction intensity data into real structural data, immediately and accurately interpretable as such, through Fourier transform tool (FTT) with no assumption and no approximation additional to those involved in kinematic theory. The first ever produced formula giving distribution of interatomic vectors, and hence distribution of interatomic distances (DID), of monatomic crystal provided together with description of possible way of obtaining it. Given examples of application relate to getting two DIDs and to using them to calculate X-ray diffracted intensity profiles, one DID was for zinc blende (ZnS) and was calculated from atom positions and the other one was for polonium and was calculated using both atom positions and appropriate formula. Software for calculating DIDs and X-ray profiles for monatomic crystals available freely. No longer needed to affect Debye scattering equation (DSE) through approximation and assumption makings before combining it with FTT to get to experimental structural data.

cond-mat.mtrl-sci↗

arXiv2020

Diffraction from inhomogeneous material systems

The static diffraction intensity distribution from large material system conceived as perfectly homogeneous system made inhomogeneous, though substitution of groups of atoms, small particles, by other groups of atoms, is explicitly expressed in terms of all possible partial contributions subsequent to the particle exchange operation. This gives the diffracted intensity as that from the homogeneous system modified by additional part and, thus, yields result that may prove to be quite useful in comparative studies of materials with the same sort of atomic network. The additional part embodies the effects of the presence of the structural disturbances and consists in two main components. One of these represents the inhomogeneity coupling with the system in its homogeneous state and, the other, represents the inhomogeneity self-coupling, the coupling of the inhomogeneities with one another. Two particular cases of deviation from homogeneity are considered in more details: the case of non-interacting inhomogeneities and that of interacting inhomogeneities. The effects on the small angle scattering (SAS) due to possible structural differences (chemical nature, atomic distribution and dimensions) between the deficient and substitute particles are given. The SAS distribution does not obey the very attractive Guinier law in some cases of non-interacting inhomogeneities.

cond-mat.mtrl-sci↗

arXiv2020

Detailed Electron Energy Loss Spectroscopy (EELS) Microanalysis of Data Collected Under Semi-Angle Less Than Both Plasmon Cutoff Angle and Incident Beam Convergence Semi-Angle

In previous work a different and powerful, analytical, technique was used to get data, such as the absolute atom concentration (AAC), specimen thickness etc., from public domain boron nitride EELS spectrum collected under a collection semi-angle, $β$, less than the plasmon cutoff angle, $θ_{c}$, but large relative to incident beam convergence, $α$. Here, seeking for some completeness, another, numerical, technique usable together with, also, $β< θ_{c}$ is described in minute detail and applied to data obtained with $β/α< 2$, so necessitating incident beam convergence-related corrections. A lot of experimental physical parameters all fully relevant to one another are produced from a single EELS spectrum. Of public domain silicon nitride, Si$_{3}$N$_{4}$, EELS spectrum used. Comparison between results producible by the two $β<θ_{c}$-related techniques made. Results range from parameters such as AAC, density, plasmon critical vector, plasmon dispersion coefficient, Fermi energy to specimen thickness. Results were obtained using version 5 of eelsMicr program and compared with existing results obtained using non EELS techniques.

cond-mat.mtrl-sci↗