I am a professor of physics at An-Najah N. University. I have established a computational physics laboratory. More than 15 graduate students have been graduated under my supervision. Four graduate students are still working under my supervision. I have taught most of the undergraduate and graduate courses in physics department.
An-Najah University Journal for Research - A (Natural Sciences)
In this paper, the nonrelativistic energies of the linear HeH2++ molecular ion have been computed... more In this paper, the nonrelativistic energies of the linear HeH2++ molecular ion have been computed using the multiperturbation theory for the ground state through fifth order. The results are very encouraging compared to the variational calculations.
The structural, mechanical, and electronic properties of rubidium iodide (RbI) have been extensiv... more The structural, mechanical, and electronic properties of rubidium iodide (RbI) have been extensively investigated utilizing the generalized gradient approximation (GGA) and the full-potential linearized augmented plane wave (FP-LAPW) approach. The potential was roughly calculated using a modified Becke–Johnson (mBJ) approximation, which increased the precision of the electronic properties. In this study, RbI is analyzed in a wide range of crystal structures, including topologies like rock salt (RS), CsCl, zinc blende (ZB), NiAs, and wurtzite (WZ), among others. Our research shows a strong relationship between the material’s physical properties and the conclusions drawn from both theoretical and experimental studies. Significantly, our results show that the RS form corresponds to RbI’s ground state. All the aforementioned topologies display wide-bandgap semiconductor capabilities, according to further examination of their electronic band structures. Notwithstanding these findings, it was discovered that RbI has a poor fracture resistance due to its low bulk modulus. Born’s stability analysis has shown that RbI is stable in the RS, CsCl, ZB, NiAs, and WZ structures. All RbI structures were discovered to have ionic bonding and to be ductile, and every stabilized system displayed anisotropic stability. Using the Cauchy pressure and Poisson’s ratio, the stiffness of the systems was evaluated, with the RS structure proving to be the stiffest. Overall, the findings illuminate the physical properties of RbI, providing valuable insights that could facilitate the creation and refinement of novel materials possessing desirable characteristics.
Abstract First-principles calculations are carried out to perform the structural properties using... more Abstract First-principles calculations are carried out to perform the structural properties using two dimensional search of equation of state (EOS), elastic constants and thermodynamic properties for zinc-blende (ZB) and wurtzite (WZ) phases of CdSexTe1−x alloys for all compositions x (x = 0, 0.25, 0.5, 0.75, 1). We have used the full-potential linearized augmented plane wave (FP-LAPW) method within the density functional theory (DFT), which has been implanted in the WIEN2k code, along with the improved generalized gradient approximation (PBE-GGA) to treat exchange-correlation functional. The mechanical and thermodynamic properties of CdSexTe1−x alloys are studied using the optimized lattice parameters from two dimensional search of EOS at zero pressure. The ZB and WZ phases of the ternary CdSexTe1−x alloys are found to be mechanically stable within PBE-GGA exchange-correlation over all the range of the Te concentrations (x = 0, 0.25, 0.5, 0.75, 1). We have found that the CdSe is mechanically the strongest material in the ternary CdSexTe1−x alloys. We concluded that the calculated values of Cauchy pressure and Poisson's ratio predict that the ionic bonds for both ZB and WZ phases of CdSexTe1−x ternary alloys are more dominant for all compositions of x(x = 0, 0.25, 0.5, 0.75, 1) within PBE-GGA exchange-correlation. Our results exhibit a non-linear relationship between elastic constants and Se concentrations. Moreover, the elastic properties of cubic (ZB) and hexagonal (WZ) phases of CdSexTe1−x alloys, including elastic constants, bulk and shear moduli are calculated and compared with available theoretical and experimental results, good agreement was found.
Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1997
The paper presents the results of viscosity determinations on aqueous solutions of hen egg-white ... more The paper presents the results of viscosity determinations on aqueous solutions of hen egg-white lysozyme at a wide range of concentrations and at temperatures ranging from 5°C to 55°C. It has been proved that, at each fixed concentration, the viscosity-temperature dependence may be quantitatively described by the modified Arrhenius formula. On the basis of the generalized Arrhenius formula, the parameters
ABSTRACT Ab initio calculations based on the density functional theory within the full-potential ... more ABSTRACT Ab initio calculations based on the density functional theory within the full-potential linearized augmented plane wave method were carried out to investigate the structural stabilities of the different crystallographic phases, the pressure-induced phase transition and the electronic properties of the platinum carbide (PtC) compound. The zinc-blende (ZB), rock-salt (RS), cesium chloride (CsCl), wurtzite (WZ), nickel arsenide (NiAs), lead monoxide (PbO) and the tungsten carbide (WC) phases were considered. The exchange and correlation potential was treated by the generalized-gradient approximation using the Perde–Burke–Ernzerhof parameterization. The thermodynamic properties such as variation of the bulk modulus, lattice constant, heat capacity, thermal expansion and Debye temperature versus pressures and temperatures are investigated. The band structure results show the metallic character of the PtC compound in all the considered phases and the present study also shows that the PtC compound crystallizes in the ZB phase at ambient conditions. The theoretical transition pressures from the ZB to RS for the NiAs, PbO and CsCl transformations were also computed.
ABSTRACT Using the framework of the density functional theory, we calculated electronic, magnetic... more ABSTRACT Using the framework of the density functional theory, we calculated electronic, magnetic and structural properties of terbium oxide (TbO) in rocksalt (RS), cesium chloride (CsCl) and zincblende (ZB). Full potential linearized augmented plane wave (FP-LAPW) method within the local spin density approximation (LSDA) and generalized gradient (PBE-GGA) approximations are used. Magnetic and non-magnetic calculations are performed and a modified version of Becke and Johnson (mBJ) exchange potential has been used to calculate the band gaps. We found that, although TbO is stable in a ferromagnetic state, it is stable in RS phase at ambient condition. Both LSDA and PBE-GGA calculations revealed that the three structures are metallic. However, using the mBJ calculation, it is clear that RS and CsCl phases of TbO compound are metallic, while ZB phase is found to be an insulator in the spin-up case and a semiconductor in the spin-down case at ambient pressure.
International Journal of Modern Physics B, Sep 17, 2015
In this paper, we report structural parameters, magnetic ordering and the electronic structure of... more In this paper, we report structural parameters, magnetic ordering and the electronic structure of the tetragonal and orthorhombic ternary iron arsenide compound [Formula: see text]. Ab initio calculations are performed by the means of full-potential linearized augmented plane waves plus local orbitals method for both spin states. The local spin density plus Hubbard potential ([Formula: see text]) and generalized gradient plus Hubbard potential ([Formula: see text]) approximations are used to treat the exchange and correlation potentials. The results mainly show that orthorhombic [Formula: see text] compound has an antiferromagnetic spin ordering. Both spin-up and spin-down polarizations are considered to investigate the band structure, density of states and electron charge density. High density of states population at the Fermi level reveals metallic character of this material. The magnetism property arises essentially from the [Formula: see text] orbital of iron atom.
An-Najah University Journal for Research - A (Natural Sciences)
In this paper, the nonrelativistic energies of the linear HeH2++ molecular ion have been computed... more In this paper, the nonrelativistic energies of the linear HeH2++ molecular ion have been computed using the multiperturbation theory for the ground state through fifth order. The results are very encouraging compared to the variational calculations.
The structural, mechanical, and electronic properties of rubidium iodide (RbI) have been extensiv... more The structural, mechanical, and electronic properties of rubidium iodide (RbI) have been extensively investigated utilizing the generalized gradient approximation (GGA) and the full-potential linearized augmented plane wave (FP-LAPW) approach. The potential was roughly calculated using a modified Becke–Johnson (mBJ) approximation, which increased the precision of the electronic properties. In this study, RbI is analyzed in a wide range of crystal structures, including topologies like rock salt (RS), CsCl, zinc blende (ZB), NiAs, and wurtzite (WZ), among others. Our research shows a strong relationship between the material’s physical properties and the conclusions drawn from both theoretical and experimental studies. Significantly, our results show that the RS form corresponds to RbI’s ground state. All the aforementioned topologies display wide-bandgap semiconductor capabilities, according to further examination of their electronic band structures. Notwithstanding these findings, it was discovered that RbI has a poor fracture resistance due to its low bulk modulus. Born’s stability analysis has shown that RbI is stable in the RS, CsCl, ZB, NiAs, and WZ structures. All RbI structures were discovered to have ionic bonding and to be ductile, and every stabilized system displayed anisotropic stability. Using the Cauchy pressure and Poisson’s ratio, the stiffness of the systems was evaluated, with the RS structure proving to be the stiffest. Overall, the findings illuminate the physical properties of RbI, providing valuable insights that could facilitate the creation and refinement of novel materials possessing desirable characteristics.
Abstract First-principles calculations are carried out to perform the structural properties using... more Abstract First-principles calculations are carried out to perform the structural properties using two dimensional search of equation of state (EOS), elastic constants and thermodynamic properties for zinc-blende (ZB) and wurtzite (WZ) phases of CdSexTe1−x alloys for all compositions x (x = 0, 0.25, 0.5, 0.75, 1). We have used the full-potential linearized augmented plane wave (FP-LAPW) method within the density functional theory (DFT), which has been implanted in the WIEN2k code, along with the improved generalized gradient approximation (PBE-GGA) to treat exchange-correlation functional. The mechanical and thermodynamic properties of CdSexTe1−x alloys are studied using the optimized lattice parameters from two dimensional search of EOS at zero pressure. The ZB and WZ phases of the ternary CdSexTe1−x alloys are found to be mechanically stable within PBE-GGA exchange-correlation over all the range of the Te concentrations (x = 0, 0.25, 0.5, 0.75, 1). We have found that the CdSe is mechanically the strongest material in the ternary CdSexTe1−x alloys. We concluded that the calculated values of Cauchy pressure and Poisson's ratio predict that the ionic bonds for both ZB and WZ phases of CdSexTe1−x ternary alloys are more dominant for all compositions of x(x = 0, 0.25, 0.5, 0.75, 1) within PBE-GGA exchange-correlation. Our results exhibit a non-linear relationship between elastic constants and Se concentrations. Moreover, the elastic properties of cubic (ZB) and hexagonal (WZ) phases of CdSexTe1−x alloys, including elastic constants, bulk and shear moduli are calculated and compared with available theoretical and experimental results, good agreement was found.
Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1997
The paper presents the results of viscosity determinations on aqueous solutions of hen egg-white ... more The paper presents the results of viscosity determinations on aqueous solutions of hen egg-white lysozyme at a wide range of concentrations and at temperatures ranging from 5°C to 55°C. It has been proved that, at each fixed concentration, the viscosity-temperature dependence may be quantitatively described by the modified Arrhenius formula. On the basis of the generalized Arrhenius formula, the parameters
ABSTRACT Ab initio calculations based on the density functional theory within the full-potential ... more ABSTRACT Ab initio calculations based on the density functional theory within the full-potential linearized augmented plane wave method were carried out to investigate the structural stabilities of the different crystallographic phases, the pressure-induced phase transition and the electronic properties of the platinum carbide (PtC) compound. The zinc-blende (ZB), rock-salt (RS), cesium chloride (CsCl), wurtzite (WZ), nickel arsenide (NiAs), lead monoxide (PbO) and the tungsten carbide (WC) phases were considered. The exchange and correlation potential was treated by the generalized-gradient approximation using the Perde–Burke–Ernzerhof parameterization. The thermodynamic properties such as variation of the bulk modulus, lattice constant, heat capacity, thermal expansion and Debye temperature versus pressures and temperatures are investigated. The band structure results show the metallic character of the PtC compound in all the considered phases and the present study also shows that the PtC compound crystallizes in the ZB phase at ambient conditions. The theoretical transition pressures from the ZB to RS for the NiAs, PbO and CsCl transformations were also computed.
ABSTRACT Using the framework of the density functional theory, we calculated electronic, magnetic... more ABSTRACT Using the framework of the density functional theory, we calculated electronic, magnetic and structural properties of terbium oxide (TbO) in rocksalt (RS), cesium chloride (CsCl) and zincblende (ZB). Full potential linearized augmented plane wave (FP-LAPW) method within the local spin density approximation (LSDA) and generalized gradient (PBE-GGA) approximations are used. Magnetic and non-magnetic calculations are performed and a modified version of Becke and Johnson (mBJ) exchange potential has been used to calculate the band gaps. We found that, although TbO is stable in a ferromagnetic state, it is stable in RS phase at ambient condition. Both LSDA and PBE-GGA calculations revealed that the three structures are metallic. However, using the mBJ calculation, it is clear that RS and CsCl phases of TbO compound are metallic, while ZB phase is found to be an insulator in the spin-up case and a semiconductor in the spin-down case at ambient pressure.
International Journal of Modern Physics B, Sep 17, 2015
In this paper, we report structural parameters, magnetic ordering and the electronic structure of... more In this paper, we report structural parameters, magnetic ordering and the electronic structure of the tetragonal and orthorhombic ternary iron arsenide compound [Formula: see text]. Ab initio calculations are performed by the means of full-potential linearized augmented plane waves plus local orbitals method for both spin states. The local spin density plus Hubbard potential ([Formula: see text]) and generalized gradient plus Hubbard potential ([Formula: see text]) approximations are used to treat the exchange and correlation potentials. The results mainly show that orthorhombic [Formula: see text] compound has an antiferromagnetic spin ordering. Both spin-up and spin-down polarizations are considered to investigate the band structure, density of states and electron charge density. High density of states population at the Fermi level reveals metallic character of this material. The magnetism property arises essentially from the [Formula: see text] orbital of iron atom.
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Papers by Mohammed Abu-Jafar