Publications Scientifiques

Now showing 1 - 5 of 5

Modeling and Simulation of Magnons Scattering Across Shear Spins in Multilayered Ferromagnetic Slabs
(SPIN, 2021) Ferrah, Leila; Bourahla, Boualem; Blizak, Salah
In this work, we introduce a computer model and theoretical approach based on the matching technique to investigate the spin precession and the magnetic properties of an ordered magnetic interface joining two ferromagnetic multilayers of type AB, made of 10 spin slabs, obtained by alternative two spin layers A and B. We simulate, particularly, the coherent magnon transmission through spins' interface, in multilayered thin ̄lms, obtained by shearing a part of the ̄lm from the other at an angle of 30. The individual and total transmittance of bulk magnons of the thin ̄lm, scattering coherently at the shearing interface zone and the localized magnonic spin states, are calculated and analyzed. The transmission and re°ection spin modes are derived as elements of a Landauer–Büttiker type scattering matrix. The results highlight the localized spin states on the interface shear domain and their interactions with incident magnons. The evolutions of the magnonic spectra can be presented for arbitrary directions of the incident magnons on the boundary zone, for all accessible frequencies in the propagating bands as well as for the magnetic exchange coupling between each spin A(B) and its adjacent sites and their spin intensity. The results demonstrate the dependence of the magnonic spectra for the perfect multilayered ̄lms and at the inhomogeneous domain of the interface shear. The analysis of the spectra illustrates the °uctuations, related to Fano resonances, due to the coupling between travelling magnons and the localized modes in the shear interface domain. The calculated spectra could yield useful information concerning the magnetic parameters of such interface slabs in multilayered ̄lms.
The effect of atmospheric optical phenomena photographed by students on learning motivation
(2018) Blizak, Meriem Djanette; Remli, S.; Blizak, Salah
The atmospheric optical phenomena (mirages, rainbows, halos, blue sky, sunset …) that we can observe in everyday life are very interesting for stimulating the students’ curiosity. This study aimed to investigate the effect of atmospheric optical phenomena photographed by university students’ on their learning motivation in geometrical optics (GO). To achieve the aim of the study, an available sample of the study composed of (200) students from the biology department of Boumerdes University, Algeria, was used. The subjects were randomly distributed into two groups: (165) of them in the experimental group and (35) in the control group. We have asked every student in the experimental group to use their smartphone or tablet to taking photos of an atmospheric optical phenomena and giving a physical explain. According to the motivation post and pres test, there were statistical significant differences in learning motivation in the favor of the experimental group
Students’ perceptions regarding the abrupt transition to online learning during the COVID-19 Pandemic: Case of Faculty of Chemistry and Hydrocarbons at the University of Boumerdes—Algeria
(American Chemical Society, 2020) Blizak, Meriem Djanette; Blizak, Salah; Bouchenak, Ouahiba; Yahiaoui, Karima
In recent months, universities around the world have been forced to cancel courses and close their doors due to the growing coronavirus epidemic. Following the government’s precautions, Algerian students were bound to quarantine regulations for their safety. Thus, they unexpectedly switched to online learning instead of face-to-face learning. Our objective of this exploratory study is to investigate the perceptions of Algerian university students regarding the abrupt transition to online learning amid the COVID-19 pandemic. To achieve this goal, an online survey with closed and open-ended questions was conducted among 380 students from the faculty of chemistry and hydrocarbons (FCH) at the University of Boumerdes—Algeria. The results showed that students have a negative perception of online learning. They are reluctant about this new digital pedagogy and prefer the traditional way of teaching to online teaching during the coronavirus pandemic
Magnetic properties of ultra-thin (Fe, Co) films coupled by Ir(001) spacers
(Elsevier, 2020) Kebaili, Aboubakr Seddik; Blizak, Salah; Bihlmayer, Gustav; Stefan, Blügel
We report on the magnetic properties of Fe1-xCox monolayers separated by Ir films ofvariable thickness, investigated using the full-potential linearized augmented plane-wave method based on the density functional theory. The interlayer exchange coupling can be used to mediate an exchange field between the layers, showing strong oscillations between antiferromagnetic and ferromagnetic coupling in terms of the Ir spacer thickness. For thin films (less than four Ir layers) a strong dependence on the chemical composition of the magnetic layers can be observed. We study also the magnetic anisotropy and the sensitivity of the in-plane exchange parameters of the magnetic layers to exchange coupling through the Ir spacer
Magnetic properties of ultra-thin (Fe, Co) films coupled by Ir(001) spacers
(Elsevier, 2020) Kebaili, Aboubakr Seddik; Blizak, Salah; Bihlmayer, Gustav; Blügel, Stefan
We report on the magnetic properties of Fe1-xCox monolayers separated by Ir films ofvariable thickness, investigated using the full-potential linearized augmented plane-wave method based on the density functional theory. The interlayer exchange coupling can be used to mediate an exchange field between the layers, showing strong oscillations between antiferromagnetic and ferromagnetic coupling in terms of the Ir spacer thickness. For thin films (less than four Ir layers) a strong dependence on the chemical composition of the magnetic layers can be observed. We study also the magnetic anisotropy and the sensitivity of the in-plane exchange parameters of the magnetic layers to exchange coupling through the Ir spacer

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