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- ItemSTRUCTURAL, ELECTRONIC, MAGNETIC, AND ELASTIC PROPERTIES OF THE FULL-HEUSLER COMPOUNDS: Sc2ZrAl, Sc2ZrIn USING FP-LAPW METHOD.(An-Najah National University, 2024-07-03) Gharabah, RubaStructural, electronic, elastic, and magnetic properties of the Full-Heusler Compounds: Sc2ZrAl, Sc2ZrIn have been investigated and examined by utilizing full potential linearized augmented plane wave method (FP-LAPW). This method provides more accurate estimations of the electronic structure of atoms. We have used the Density Functional Theory (DFT), which is a computational quantum mechanical modelling method being implemented in the WIEN2k package. FP-LAPW method is an application of Kohn-Sham (DFT), which typically goes with the study of core and valence electrons, the ground state density, total energy, and Kohn-Sham eigenvalues (energy bands) of a many-electron system. Structural parameters (bulk modulus, lattice parameters and first pressure derivatives) have been investigated by applying the generalized gradient approximation (PBE-GGA). Also, the modified Becke-Johnson (mBJ) was used computationally to develop and enhance the calculated value of energy band gap for these compounds. Mechanically, we identified that the normal full-Heusler compounds Sc2ZrAl and Sc2ZrIn were stable, while the inverse full-Heusler compounds Sc2ZrAl and Sc2ZrIn were unstable. This result agrees with previous studies.
- ItemWAFER PROBING MEASUREMENTS OF ITkPix-V1 FOR ITk PIXEL ATLAS UPGRADE(An-Najah National University, 2024-07-22) Salahat, HosniaThis thesis is related to a Toroidal LHC Apparatus (ATLAS), the biggest general-purpose detector at the Large Hadron collider (LHC). Inside the LHC ring, two high energy hadron beams collide. This collision needs to be detected to check the predictions of particle physics theories, such as the properties of the Higgs boson, which is so crucial to the Standard Model. For that, ATLAS and other detectors were built. Researchers need to boost the LHC's performance by increasing its integrated luminosity by a factor of ten beyond its design value to maximize discoveries possibility in 2029, known as the High Luminosity-Large Hadron Collider (HL-LHC) plan. ATLAS detector is going under upgrading processes to cope with this higher luminosity, in which its inner detector (ID) that is composed partially of silicon is going to be replaced by a new inner tracker (ITk) consists completely of silicon. The new ITk is composed of a strip detector and pixel detector. The building blocks of the ITk’s pixel detector are the pixel modules which contains readout chips called the ITkPix-V1. Those chips are going under tests to check its suitability to be used in the new ITk. One of those tests is the wafer probing tests. In Laboratoire De Physique Des 2 Infinite Irène Joliot-Curie (IJCLab), the wafer propping set-up used for this task has to undergo a quality control process to decide its fit to do the tests on the chips, so the main topic of this thesis is analyzing the results of the tests done by the wafer probing set-up of IJCLab on the ITkPix-V1 chips and comparing it to reference measurements done by the University of Bonn on the same chips in order to help qualifying the set-up of IJCLab to do the wafer probing tests. Part of the test results were similar to the reference results while some were not. Depending on the analysis done, some reasons that cause the non consistent results were found. Key Words: ATLAS, LHC, HL-LHC, ITk, ITkPix-V1.
- ItemELECTRIC FIELD EFFECT IN MONOLAYER OF GRAPHENE(2022-09-05) Salsabeel Khalel SalehBackground: Graphene is a two-dimensional nanomaterial. The theory of graphene was laid out for the first time in 1947when P. R. Wallace looked at the electronic band structure of graphene. Many researchers have studied the properties of graphene in the presence of an electric field. This study has looked at the dynamics of electron in a two- dimensional monolayer graphene in the presence of a static and uniform electric field. Three different orientations of the electric field have been considered: E ⃗=E_x i ̂ ,E ⃗=E_y j ̂ and E ⃗=E_x i ̂+E_y j ̂ where x and y are arbitrary directions. Methodology: The dynamical expressions for the velocity and position of an electron in an oriented- electric field have been derived from the dispersion relation. The figures in the calculations were drawn by using the Mathematica program. Results: The electric field depended on the frequency of w_B.Because the electric field E ⃗ is implicitly related to electron momentum k_xand k_y, it was possible control it as they change. Moreover, when the applied electric field E ⃗ is in the x and y direction together the electron's behavior in the monolayer graphene is influenced by an angle α. Conclusion: These findings showed that if an electric field E ⃗ is applied to an electron along the x axis, the electron's Bloch oscillation would disappear in the x direction but would never happen in the y direction. And the electron's movement over the Dirac points would double the amplitude and period. Keywords: Electric field; Bloch oscillation; graphene; position; velocity.
- ItemMAGNETIC AND ELECTRONIC PROPERTIES OF InAs ANISOTROPIC DOPED QUANTUM DOT WITH SPIN-ORBIT COUPLING: COMPUTATIONAL STUDY(An - Najah National University, 2023-05-15) Ayham Anwar Ahmad ShaerThe anisotropic quantum dot (QD) Hamiltonian has been solved using the diagonalization method in the presence of a perpendicular magnetic field and Gaussian impurity, considering both types of spin-orbit interaction (SOI): Rashba and Dresselhaus. The diagonalization process has been carried out using the one-dimensional harmonic oscillator basis. The acceptor impurity's presence significantly affects the system's eigensolution, specifically causing an interesting level crossing between the states and changing the ground state order. Furthermore, the impurity's strength, position, and spatial stretch have been investigated, and the result shows that the impurity plays an important role in manipulating the QD properties. The magnetization and magnetic susceptibility as important quantities of the QD system made from InAs are studied. The results show a diamagnetic-paramagnetic phase transition at low temperatures due to the impurity presence. This magnetic transition strongly correlates with the impurity profiles (strength, position, and influence domain), magnetic field, and temperature. As the strength of the impurity increases, the diamagnetic-paramagnetic transition occurs at a lower value of the magnetic field. In addition, the effective Lande factor g of the system has been studied. The result shows that, as the electric field increases, the Rashba SOI increases |g|, while the Dresselhaus SOI reduced |g| of the QD. Furthermore, in the presence of both types of SOI, increasing the electric field enhances the |g| since in the InAs material, the Rashba SOI dominates the Dresselhaus SOI. The result emphasizes the role of Rashba SOI in spintronics devices. The confinement strength effect on the g has been investigated, the g shows a peak value at particular confinement strength. In addition, the anisotropy of the QD shows a significant role in controlling g. The density of states of the system has also been computed to physically describe the impact of each system parameter on the energy spectrum. As the magnetic field turns on, the figures demonstrate how the anisotropy of the confinement potential also causes the harmonic oscillator symmetry to be broken.
- ItemSTRUCTURAL, ELECTRONIC, MAGNETIC AND ELASTIC PROPERTIES OF THE FULL-HEUSLER COMPOUNDS: SC2TIAL, SC2TISI USING FP-LAPW METHOD(An Najah National University, 2022-02-27) Mahmoud Elaiyan Al-Masri, KhadejahIn this study, we investigate the structural, electronic, magnetic and elastic properties of the normal and inverse Heusler Sc2TiAl and Sc2TiSi compounds using a full potential linearized augmented plane wave (FP-LAPW) method, within the density functional theory. The band structure and DOS calculations are made within the generalized gradient approximation (GGA) and modified Becke Johnson approaches (mBJ-GGA), employed in the Wien2K code. The density of states (DOS) and band structure (BS) show metallic nature. We calculate the structural properties such as the lattice constants, bulk moduli and elastic properties like Poisson ratio v, shear modulus S, Young modulus (Y) and B/s ratio. Results are in agreement with previous studies so these properties provide a road map for its possible uses in electronic devices.