Said Al Azar
@zu.edu.jo
Zarqa university/Assistant Professor of Physics
RESEARCH, TEACHING, or OTHER INTERESTS
Condensed Matter Physics, Electronic, Optical and Magnetic Materials, General Materials Science, Metals and Alloys
Scopus Publications
Scopus Publications
Anas Y. Al-Reyahi, Said M. Al Azar, Saber Saad Essaoud, Mohammed Elamin Ketfi, and Mufeed Maghrabi
Elsevier BV
Akram Aqili, Anas Y. Al-Reyahi, Said M. Al Azar, Saber Saad Essaoud, Mohammed Elamin Ketfi, Mufeed Maghrabi, Nabil Al Aqtash, and Ahmad Mufleh
Elsevier BV
Omer Kabi, Mohammed S. Abu-Jafar, Mahmoud Farout, Ahmad A. Mousa, Abdelmadjid Bouhemadou, Nazia Erum, Said M. Azar, Ahmed Bassalat, Hadil Abualrob, Ahmad Y. Thabaineh,et al.
American Chemical Society (ACS)
We presented the results of various aspects related to structural, elastic, electronic, dynamic, and magnetic parameters of cubic perovskite CeCrO3 by means of the full-potential linearized augmented plane wave (FP-LAPW) approach. The calculation of the unit cell volume against the total energy curve confirms that CeCrO3 exhibits higher energetic stability in the ferromagnetic (FM) order. Calculated structural aspects at equilibrium demonstrate excellent similarity to present information, lending credibility to our results. Moreover, monocrystalline elastic constants have been analyzed numerically. These constants provide insights into several related properties, including elastic anisotropy, mechanical stability, and several polycrystalline elastic aspects. Furthermore, the phonon dispersion curves obtained from our calculations reveal the existence of soft modes, which suggests the potential metastability of CeCrO3. Through an analysis of the energy band dispersions, the half-metallic nature of this material is confirmed, such as Eg = 3.00 and 3.13 eV for the HM state within generalized gradient approximations Perdew–Burke–Ernzerhof (GGA-PBE) and Tran–Blaha modified Becke–Johnson (TB-mBJ) calculations, respectively, as well as the FM total magnetic moment of 4.000 μB. Partial density of states (PDOS) aided in identifying the electronic states that contribute to the energy bands. Finally, the computed total magnetic moment aligns fit the theoretical findings available in the literature.
Nabil Al-Aqtash, Anas Y. Al-Reyahi, Said Al Azar, Saber Saad Essaoud, Mufeed Maghrabi, Ahmad Mufleh, Mohammed Elamin Ketfi, and Khadidja Berarma
Elsevier BV
Anas Y. Al-Reyahi, Ahmad Mufleh, Said M. Al Azar, Mufeed Maghrabi, Nabil Al Aqtash, Saber Saad Essaoud, Khadidja Berarma, Adel Shaheen, Mohammed Elamin Ketfi, and Ahmad A. Mousa
Elsevier BV
Saber Saad Essaoud, Mohammed Elamin Ketfi, Said Al Azar, Anas Y. Al-Reyahi, and Ahmad Mufleh
Springer Science and Business Media LLC
Mohammed Elamin Ketfi, Saber Saad Essaoud, Said Al Azar, and Anas Y. Al-Reyahi
Springer Science and Business Media LLC
Mohammed Elamin Ketfi, Saber Saad Essaoud, Said M Al Azar, Anas Y Al-Reyahi, Ahmad A Mousa, and Nabil Al-Aqtash
IOP Publishing
Abstract We report an analysis of the structural, electronic, mechanical, and thermoelectric properties of oxide double perovskite structures, specifically the compounds Ba2MgReO6 and Ba2YMoO6. Our study employs first-principles density functional theory (DFT) as the investigative methodology. The electronic attributes of the examined compounds are explained by investigating their energy bands, as well as the total and partial density of states. The computational evaluation of the electronic band structure reveals that both compounds exhibit an indirect band gap semiconductor behavior in the spin-down channel, while demonstrating metallic properties in the spin-up channel. The magnetic attributes indicate a ferromagnetic nature, thus categorizing some double perovskite compounds as materials displaying half-metallic ferromagnetism (HM-FM) in addition to some other properties such as metallic and semiconductor in paramagnetic or antiferromagnetic states. The outcomes derived from the analysis of elastic constants confirm the mechanical robustness of the studied double perovskite compounds. Notably, the computed data for bulk modulus (B), shear modulus (G), and Young’s modulus (E) for Ba2MgReO6 surpass those of Ba2YMoO6. The calculated ratio of Bulk to shear modulus (B/G) indicates that both compounds possess ductile characteristics, rendering them suitable for device fabrication. Furthermore, both compounds display outstanding electronic and elastic properties, positioning them as promising contenders for integration within mechanical and spintronic devices. Finally, we investigate into the thermoelectric potential by evaluating parameters such as the Seebeck coefficient, electrical conductivity, thermal conductivity, figure of merit, and power factor. This assessment is conducted using the semiclassical Boltzmann theory and the constant relaxation time approximation, implemented through the BoltzTraP code. The results indicate that the investigated double perovskite oxides hold promise for utilization in thermoelectric applications.
Mufeed Maghrabi, Anas Y. Al-Reyahi, Nabil Al Aqtash, Said M. Al Azar, Adel Shaheen, Ahmad Mufleh, and Bashar Shaban
Elsevier BV
Mohammed Elamin Ketfi, Saber Saad Essaoud, Said Al Azar, Anas Y. Al-Reyahi, Ahmad A. Mousa, and Ahmad Mufleh
Springer Science and Business Media LLC
Yousef M. Odeh, Said M. Azar, Anas Y. Al-Reyahi, Ahmad A. Mousa, Emad K. Jaradat, and Nabil Al Aqtash
AIP Publishing
In this paper, by using density functional theory (DFT), the structural, electronic, and optical properties of cubic and orthorhombic perovskites BaZrS3−xSex are explored. The lattice parameters increase when the substitution of S/Se atoms is applied, whereas the bulk moduli decrease. The density of states curves showed a strong hybridization between Zr-d and S-p/Se-p orbitals. Furthermore, the obtained bandgaps of the orthorhombic phases are direct (Γ–Γ), whereas they are indirect (R–Γ) for the cubic phase. When substituting sulfur with selenium, the bandgap decreases from 0.963 to 0.705 eV for the orthorhombic phase and from 0.655 to 0.288 eV for the cubic phase. The dielectric function showed that the optical bandgaps are between 0.7 and 0.5 eV for orthorhombic BaZrS3–xSex, which is in the infra-red spectrum, and it was between 0.7 and 0.25 eV for the cubic phase. The reflectivity was in the range of [26%–31%] at low energies, which can be considered quite reflective. The refractive index for the orthorhombic phase increased from 3.0 to 3.5 at low energies and from 3.6 to 3.9 for the cubic phase, which indicates high absorption at those values of energy. The result obtained indicates that chalcogenide perovskites BaZrS3−xSex are good candidates for future photovoltaic applications such as tandem solar cells.
Saber Saad Essaoud, Said M Azar, Ahmad A Mousa, and Anas Y Al-Reyahi
IOP Publishing
Abstract The density functional theory as a computational approach was used to explore the ferrimagnetic semiconducting behavior of Dy2CoMnO6 double perovskite compound in both spin-up and spin-down directions. Thermodynamic stability was confirmed in a wide pressure range set to 30 GPa. Both scalar and full relativistic calculations are used to estimate the spin–orbit effect. The topological distribution of the charge density and the net effective charge of each atom are studied based on the Quantum Theory of Atoms in Molecules (QTAIM) as implemented in Bader code, Besides this, the different QTAIM atomic basins descriptors such as electron density ρ b , Laplacian of the electron density ∇ 2 ρ b , potential electronic energy density V b , kinetic electronic energy density G b and density of the total electronic energy H b at bond critical points (BCPs) are estimated using CRITIC2 software where the ionic type for Dy-O, Co-O, and Mn-O bonds are evaluated. Holes and electrons have different effective masses, their thermoelectric properties appear high figure of merit (ZT) exceeding 0.5 for temperatures greater than 500 K in the negative chemical potential region, suggesting that doping with holes might be more favorable for thermoelectric efficiency than doping with electrons.
Khadejah M. Al-Masri, Mohammed S. Abu-Jafar, Mahmoud Farout, Diana Dahliah, Ahmad A. Mousa, Said M. Azar, and Rabah Khenata
MDPI AG
In this article, the structural, elastic, electronic, and magnetic characteristics of both regular and inverse Heusler alloys, Sc2TiAl and Sc2TiSi, were investigated using a full-potential, linearized augmented plane-wave (FP-LAPW) method, within the density functional theory. The optimized structural parameters were determined from the minimization of the total energy versus the volume of the unit cell. The band structure and DOS calculations were performed 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) indicate the metallic nature of the regular structure of the two compounds. The total spin magnetic moments for the two compounds were consistent with the previous theoretical results. We calculated the elastic properties: bulk moduli, B, Poisson’s ratio, ν, shear modulus, S, Young’s modulus (Y), and the B/s ratio. Additionally, we used Blackman’s diagram and Every’s diagram to compare the elastic properties of the studied compounds, whereas Pugh’s and Poisson’s ratios were used in the analysis of the relationship between interatomic bonding type and physical properties. Mechanically, we found that the regular and inverse full-Heusler compounds Sc2TiAl and Sc2TiSi were stable. The results agree with previous studies, providing a road map for possible uses in electronic devices.
Saber Sâad Essaoud, Said M Al Azar, Ahmad A Mousa, and Riad S Masharfe
IOP Publishing
Abstract Born effective charges Z(i),β α *, dielectric tensors ε α,β and the dynamic stability for AgMgF3 and KMgF3 compounds were treated based on the harmonic and quasi-harmonic theory implemented in phonopy code. The band gap for both compounds, and the effective masses of electrons and holes are calculated at different pressures using the TB-mBJ (GGA) approximation within the framework of the density functional theory. Furthermore, absorption coefficient, refractive index, extinction coefficient, reflectivity, and optical conductivity, for both compounds, were calculated. On the other hand, we studied the nature of atomic bonds by the topological distribution of the charge density as well as computing the effective charge of each atom based on the Quantum Theory of Atoms in Molecules (QTAIM) as implemented in Bader code, therefore the ionic type for bonds was explored. The mechanical stability was verified the elastic behavior at the equilibrium ground-state for both compounds. Thermal properties such as heat capacity at constant volume, entropy, Debye temperature, and thermal expansion coefficient are treated depending on the quasi-harmonic model. They are examined under both pressure and temperature influences. The thermoelectric properties of the compound AgMgF3 showed a high figure of merit (ZT) reached 0.75 at a temperature of 300 K in the case if it was grafted with a concentration of 1021 cm−3 of n-type.
Anas Y. Al-Reyahi, Said Al Azar, Ahmad A. Mousa, Saber Saad Essaoud, Mufeed Maghrabi, Khadidja Berarma, Akram Aqili, Ahmad Mufleh, and Heba I. Abu Radwan
Elsevier BV
Khadidja Berarma, Saber Sâad Essaoud, Said Al Azar, Anas Y. Al-Reyahi, Ahmad A. Mousa, and Ahmad Mufleh
Informa UK Limited
ABSTRACT A full-potential linear augmented plane wave (FP-LAPW) has been used to study the structural, electronic, and optical properties of double half-Heusler alloys X2FeY′Sb2 with X≡Zr, Hf and Y′≡Pd, Ni. Electronic band structures and densities of states calculations of the four studied double half-Heusler alloys indicate that they are semiconductors with an indirect gap. The optical spectra of dielectric constants, refractive indices, reflectivity, and light absorption are also discussed. In the energy range of 8–14 eV, the calculated optical properties and mainly the absorption spectrum show very high UV absorption. Additionally, DFT calculations were combined with Boltzmann transport theory to estimate the thermoelectric properties, such as the thermal and electrical conductivity, Seebeck coefficient, and figure of merit (ZT), versus the change of temperature and chemical potential. These alloys possess a suitable band gap for diverse optoelectronic applications, encompassing photovoltaics, UV sensors, and solar cells.
Nabil Al Aqtash, Said M. Al Azar, Anas Y. Al-Reyahi, Ahmad Mufleh, Mufeed Maghrabi, Saber Saad Essaoud, Khadidja Berarma, and Ahmad A. Mousa
Informa UK Limited
ABSTRACT Structural, elastic, electronic, optical, and thermoelectric properties of cubic double perovskites X2AgBiBr6 (X = Li, Na, K, Rb, Cs) were investigated using the density functional theory (DFT) method. The DFT calculations were carried out with various exchange-correlation potentials, e.g. LDA, GGA-PBE, GGA-WC, and hybrid functionals (YS-PBE0). Structural and elastic properties of X2AgBiBr6 demonstrate that these compounds are ionically bonded, elastically stable, ductile, and anisotropic. Calculations show that the compounds are semiconductors with indirect bandgap at the (X- L) point, with bandgap values of 2.124, 2.222, 2.198, 2.209, and 1.902 eV for X2AgBiBr6 (X = Li, Na, K, Rb, and Cs), respectively. Due to their distinguishing optical characteristics and indirect wide bandgap, these compounds might be utilised as absorber layers in solar cells and other optoelectronic devices. Moreover, thermoelectric properties show that the Figure of Merit (ZT) has values of 0.713, 0.723, 0.721, 0.726, and 0.728 for X2AgBiBr6 (X = Li, Na, K, Rb, Cs). The Figure of Merit shows a plateau in the temperature range of 500–900 K, which corresponds to the highest value of ZT. All investigated compounds have holes as the majority of charge carriers. Thermoelectric properties of X2AgBiBr6 compounds reveal that these compounds can be employed in thermoelectric devices.
Mohammed S. Abu-Jafar, Raed Jaradat, Mahmoud Farout, Areej Shawahneh, Ahmad A. Mousa, Khalid Ilaiwi, Rabah Khenata, and Said M. Azar
Informa UK Limited
ABSTRACT The structural parameters, electronic, optical, and elastic properties of Niobium Carbide (NbC) compound within four different structures: rock-salt (RS), wurtzite (WZ), cesium chloride (CsCl), and Nickel Arsenide (NiAs) are examined using the Full-Potential Linearized-Augmented Plane Wave (FP-LAPW). The exchange–correlation potential (VXC) has been treated by Perdew, Burke, and Ernzerhof's generalized gradient approximation (PBE-GGA) when structural properties, transition pressure, and elastic properties are estimated. For electronic properties, in addition to (PBE-GGA), the modified Becke–Johnson (mBJ-GGA) was used for increased accuracy. Present results show that the RS of NbC is the most stable among the four examined structures with the lowest equilibrium energy. The calculated lattice constants are in good agreement with the former calculations. The elasticity and the formation energy calculations show that NbC is stable within the four studied structures. The electronic band structure calculations of NbC show that it has a metallic nature in the four considered structures.
Raed T. Jaradat, Mohammed S. Abu-Jafar, Mahmoud Farout, Said M. Azar, Rabah Khenata, and Ahmad A. Mousa
AIP Publishing
The electronic, magnetic, and optical properties of NaS and NaSe compounds have been studied by using first-principles calculations based on density-functional theory and full-potential linearized augmented plane-wave method. The Perdew–Burke–Ernzerhof generalized gradient approximation (PBE-GGA) and modified Becke–Johnson (mBJ-GGA) have been used to deal with the exchange-correlation potential. The PBE-GGA and mBJ-GGA electronic calculation of the spin-up configuration shows an insulating behavior, while the spin-down shows a metallic behavior. In addition, both PBE-GGA and mBJ-GGA agree that the total magnetic moment per unit cell for these compounds is 1 μB. From optical calculations, we see that ε1(0) value in the spin-up channel is positive, which shows an insulating character, while it has a large negative value for the spin-down configuration, which shows a metallic character. The NaS and NaSe refractive index n(ω) indicates a metallic demeanor as the real and imaginary parts of the dielectric constant.
Sara J. Yahya, Mohammed S. Abu-Jafar, Said Al Azar, Ahmad A. Mousa, Rabah Khenata, Doha Abu-Baker, and Mahmoud Farout
MDPI AG
In this paper, the full-potential, linearized augmented plane wave (FP-LAPW) method was employed in investigating full-Heusler Co2CrA1’s structural, elastic, magnetic and electronic properties. The FP-LAPW method was employed in computing the structural parameters (bulk modulus, lattice parameters, c/a and first pressure derivatives). The optimized structural parameters were determined by generalized gradient approximation (GGA) for the exchange-correlation potential, Vxc. Estimating the energy gaps for these compounds was accomplished through modified Becke–Johnson potential (mBJ). It was found that the conventional Heusler compound Co2CrA1 with mBJ and CGA approaches had a half-metallic character, and its spin-down configuration had an energy gap. It was also found that the conventional and inverse Heusler Cr2MnSb and tetragonal (139) (Co2CrA1, Cr2MnSb) compounds with a half-metallic character had direct energy gaps in the spin-down configuration. To a certain degree, the total magnetic moments for the two compounds were compatible with the theoretical and experimental results already attained. Mechanically, we found that the conventional and inverse full-Heusler compound Co2CrAl was stable, but the inverse Cr2MnSb was unstable in the ferromagnetic state. The conventional Heusler compound Cr2MnSb was mechanically stable in the ferromagnetic state.
Ahmad A. Mousa, Said M. Al Azar, Saber Sâad Essaoud, Khadidja Berarma, Aymen Awad, Nada T. Mahmoud, Emad K. Jaradat, and Mohammed S. Abu-Jafar
Wiley
The structural, elastic, electronic, magnetic, and thermoelectric properties of MgEu2X4 (X = S and Se) spinel compounds are investigated computationally. Calculations are performed using the full‐potential linearized augmented plane wave (FP‐LAPW) method within the Perdew, Burke, and Ernzerhof generalized gradient approximation (PBE‐GGA), GGA + U, and modified Becke–Johnson (mBJ‐GGA) approximations. The band structure and density of states results from the three exchange‐correlation approximation methods (mBJ, GGA + U, and PBE) show that these spinel compounds are fully spin‐polarized. Also, they possess a half‐metallic character in the spin‐down channel with a direct bandgap (Γ–Γ) of about 3.44, 2.712, and 2.472 eV for MgEu2S4 and 2.89, 2.285, and 2.017 eV for MgEu2Se4, respectively. The formation of both compounds is energetically favorable based on the results of the total energy and cohesive energy calculations. Furthermore, the two compounds are chemically and mechanically stable, as concluded from cohesive energy and elastic calculations. The elastic calculations reveal that both spinel compounds are ductile materials. The ionic bonds are predominant. The quasi‐harmonic model has also been used to investigate the influences of temperature and pressure on thermal characteristics. The thermoelectric behavior is studied using the BoltzTraP code. Both systems show good thermoelectric properties for the spin‐down channel.
Ahmad A. Mousa, Tarik Ouahrani, Said M. Azar, Mohammed S. Abu-Jafar, Rabah Khenata, and Mahmoud Farout
Elsevier BV
Khadidja Berarma, Saber Sâad Essaoud, Ahmad A Mousa, Said M Azar, and Anas Y Al-Reyahi
IOP Publishing
Abstract A computational research study of the structural, electronic, and optical characteristics of double half-Heusler alloys Ta2FeNiSn2 and Nb2FeNiSn2 is presented by performing ab initio calculations. The density functional theory framework employs the full-potential linearized augmented plane wave method to solve Kohn–Sham equation as implemented in the Wien2k code. The exchange-correlation potential is processed by using the local density approximation and the generalized gradient approximation–Perdew, Burke, and Ernzerhof approximations to calculate the total energy and other physical properties. The obtained results showed that both alloys possess high cohesive energies, where Nb2FeNiSn2 (7.213 eV atom−1) is more consistent than Ta2FeNiSn2 (6.249 eV atom−1), these remarkable results support the structural stability for both alloys. Also, the thermodynamic stability of both compounds was confirmed through calculating the formation energy as the obtained results were close to the results obtained in as well as given the Open Quantum Materials Database. Electronic characteristics and chemical bonding are illustrated and discussed by computing the electron charge density, density of states, and band structure. Both alloys show semiconductor behavior with (∼0.5 eV) indirect energy bandgap. Also, we have calculated and analyzed the complex dielectric function, absorption coefficient, as well as, reflectivity spectra for both compounds. The semi local Boltzmann transport theory has been employed to treat temperature effect on thermoelectric properties of Ta2FeNiSn2 and Nb2FeNiSn2 compounds where the obtained results appears that both compounds have high coefficient at the normal condition, and they also have a good power factor at the Fermi level, which emphasizes that the thermoelectric efficiency of the two compounds is good and does not require doping. Also, depending on quasi-harmonic model was used for estimating the heat capacity, the lattice thermal conductivity, the thermal expansion and the Debye temperature under the pressure effects.