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Bahmad L.,Mohammed V University | Masrour R.,Mohammed V University | Masrour R.,App Quality | Hlil E.K.,CNRS Neel Institute | And 3 more authors.
Superlattices and Microstructures | Year: 2013

Self-consistent ab initio calculations, based on DFT (Density Functional Theory) approach and using FLAPW (Full potential Linear Augmented Plane Wave) method, are performed to investigate both electronic and magnetic properties of the Ni/Cu superlattices. Polarized spin and spin-orbit coupling are included in calculations within the framework of the ferromagnetic state between two adjacent Ni/Cu superlattices. Within the framework of Monte Carlo simulations, we examine the magnetic properties in these binary Ni/Cu superlattices, modeled by σ = 1/2 and S = 1 spins. The considered Hamiltonian takes into account nearest-neighbor interactions, the crystal field Δ, and an external magnetic field h. The magnetizations of the two compounds are calculated versus the temperature for different spin configurations. The magnetizations versus the interface exchange interaction J⊥ and magnetic field are deduced. The magnetic hysteresis cycle is examined for the two configurations, for fixed values of the temperature. © 2013 Elsevier Ltd. All rights reserved.


Masrour R.,App Quality | Masrour R.,Mohammed V University | Hamedoun M.,Institute for Nanomaterials and Nanotechnologies | Benyoussef A.,Mohammed V University | Benyoussef A.,Institute for Nanomaterials and Nanotechnologies
Applied Surface Science | Year: 2012

The phase transition and magnetic properties of a ferromagnet spin-S, a disordered diluted thin and semi-infinite film with a face-centered cubic lattice are investigated using the high-temperature series expansions technique extrapolated with Padé approximants method for Heisenberg, XY and Ising models. The reduced critical temperature of the system τ c is studied as function of the thickness of the thin film and the exchange interactions in the bulk, and within the surfaces J b, J s and J, respectively. It is found that τ c increases with the exchange interactions of surface. The magnetic phase diagrams (τ c versus the dilution x) and the percolation threshold are obtained. The shifts of the critical temperatures T c(l) from the bulk value (T c(∞)/T c(l) - 1) can be described by a power law l -λ, where λ = 1/ is the inverse of the correlation length exponent. © 2011 Elsevier B.V. All rights reserved.


Hamedoun M.,Institute for Nanomaterials and Nanotechnologies | Masrour R.,App Quality | Masrour R.,Mohammed V University | Mounkachi O.,Institute for Nanomaterials and Nanotechnologies | And 4 more authors.
Physica Scripta | Year: 2013

CoFe2O4 and MnFe2O4 ferrite nanoparticles were prepared by the co-precipitation method. The structural evolutions of the nanophase have been studied. The refinement result showed that the type of cationic distribution over the tetrahedral and octahedral sites in the nanocrystalline lattice is a partially inverse spinel. The morphology of the samples has been determined using transmission electron microscopy and the magnetic properties of the samples are given. The gap energy is calculated using the Korringa-Kohn-Rostoker method combined with a coherent potential approximation and using optical measurements for CoFe2O4 and MnFe2O4. This study has been extended theoretically to the mixed spinel ferrites, FeCoMnxFe1-xO4. Indeed, the saturation magnetization, the critical temperature, exchange interactions and Curie constant for the cation distribution , have been calculated. The high temperature series expansion combined with the Padé approximant are used to determine the critical temperature and critical exponent (γ) associated with the magnetic susceptibility of mixed spinels. © 2013 The Royal Swedish Academy of Sciences.


Masrour R.,App Quality | Masrour R.,Mohammed V University | Bahmad L.,Mohammed V University | Hamedoun M.,Institute for Nanomaterials and Nanotechnologies | And 3 more authors.
Journal of Superconductivity and Novel Magnetism | Year: 2014

The magnetic properties of a diluted ferromagnetic-antiferromagnetic Ising model on a nanographene lattice, constituted of pure ferromagnetic layer with spin S=5/2 and diluted antiferromagnetic layer with a spin σ=3/2, have been studied using Monte Carlo simulations. The considered Hamiltonian takes into account nearest-neighbor interactions, crystal field, and external magnetic field. The calculated magnetizations versus the dilution of the bonds in block A depend on the temperature, crystal field Δ, and external magnetic field h. The saturation magnetization and the magnetic remanent are also obtained for the two blocks. © 2013 Springer Science+Business Media New York.


Masrour R.,App Quality | Masrour R.,Mohammed V University | Hamedoun M.,Institute for Nanomaterials and Nanotechnologies | Benyoussef A.,Mohammed V University | Benyoussef A.,Institute for Nanomaterials and Nanotechnologies
Physica B: Condensed Matter | Year: 2012

The exchange interactions (J BB and J AB are the intra and the inter-sublattice exchange interactions between neighbouring spins, respectively) are obtained by using the general expressions of canting angle and critical temperature obtained by mean field theory of Li 0.5Fe 2.5-2xAl xCr xO 4. The expression of magnetic energy of Li 0.5Fe 2.5-2xAl xCr xO 4 is obtained for different spin configurations and dilution x. The saturation magnetisation of Li 0.5Fe 2.52xAl xCr xO 4 is obtained with different values of dilution x. The magnetic phase diagram of Li 0.5Fe 2.52xAl xCr xO 4 materials is obtained by high temperature series expansions (HTSEs). The critical exponent associated with the magnetic susceptibility of Li 0.5Fe 2.5-2xAl xCr xO 4 is deduced. © 2012 Elsevier B.V. All rights reserved.


Masrour R.,University Sidi Mohammed Ben Abdellah | Masrour R.,Mohammed V University | Hamedoun M.,Institute for Nanomaterials and Nanotechnologies | Benyoussef A.,Mohammed V University | Benyoussef A.,Institute for Nanomaterials and Nanotechnologies
Journal of Magnetism and Magnetic Materials | Year: 2010

The exchange interactions and the magnetic exchange energies are calculated by using the mean field theory and the probability law of Zn1-xMnxCr2O4 nanoparticles. The high-temperature series expansions have been applied in the spinels Zn1-xMnxCr2O4 systems, combined with the Padé approximants method, to determine the magnetic phase diagram, i.e. TC versus dilution x. The critical exponent associated with the magnetic susceptibility (γ) is deduced. The obtained value of γ is insensitive to the dilution ratio x and may be compared with other theoretical results based on the 3D Heisenberg model. © 2009.


Masrour R.,University Sidi Mohammed Ben Abdellah | Masrour R.,Mohammed V University | Hamedoun M.,Expert Aupres de lAcademie Hassan II des science et Techniques | Hamedoun M.,Institute for Nanomaterials and Nanotechnologies | And 2 more authors.
Journal of Alloys and Compounds | Year: 2010

The magnetic properties of diluted spinels Zn1-xM xFe2 O4 (M = Mg, Ni) systems have been studied by mean field theory, probability law and high-temperature series expansions method in the range 0 ≤ x ≤ 1. The exchange interactions are calculated by the first and second theory, respectively. The magnetic phase diagrams of Zn1-xMxFe2O4 (M = Mg, Ni) are calculated by the high-temperature series expansions, combined with the Padé approximants method. The critical exponent associated with the magnetic susceptibility (γ) is deduced. © 2010 Elsevier B.V. All rights reserved.


Masrour R.,University Sidi Mohammed Ben Abdellah | Masrour R.,Mohammed V University | Hamedoun M.,Institute for Nanomaterials and Nanotechnologies | Benyoussef A.,Mohammed V University | Benyoussef A.,Institute for Nanomaterials and Nanotechnologies
Journal of Superconductivity and Novel Magnetism | Year: 2011

The electronic and the magnetic of semimagnetic semiconductors Hg 1-x Mn x Te are studied. The magnetic phase diagrams have been determined by the replica method in the framework of the XY model using variational principle. A spin glass state has been obtained for x


Masrour R.,Cady Ayyed University | Masrour R.,Mohammed V University | Hamedoun M.,Institute for Nanomaterials and Nanotechnologies | Benyoussef A.,Mohammed V University | Benyoussef A.,Institute for Nanomaterials and Nanotechnologies
Chemical Physics Letters | Year: 2011

The magnetic properties of mixed spinels (Znx2+Fe1-x3+)A(Mn1- x2+Fe1+x3+)BO42- ferrite are studied. The effect of Zn doping on magnetic properties of MnFe2O4 ferrite spinel has been studied. The exchange interactions (JAA, JAB and J BB) and exchange constants (λAA, λAB and λBB) of this material are obtained. The general expression of saturation magnetization, the critical temperature and Curie constant (C) are obtained by the mean field theory. The high temperature series expansion combined with the Padé approximant is given to determinate the critical temperature of the mixed spinels. The critical exponent associated with the magnetic susceptibility is given for different values of Padé. © 2011 Elsevier B.V. All rights reserved.


Masrour R.,Mohammed V University | Hamedoun M.,Institute for Nanomaterials and Nanotechnologies | Benyoussef A.,Mohammed V University | Benyoussef A.,Institute for Nanomaterials and Nanotechnologies
Journal of Superconductivity and Novel Magnetism | Year: 2011

magnetic properties of semi-conductor CuTi 2-2xCr 2xS 4 systems have been studied. The nearest neighbour j 1(x) and the next-neighbour super-exchange J 2(x) interactions are evaluated by using the mean field theory for this spinel CuTi 2-2xCr 2xS 4 system. The magnetic energy, the intraplanar and the interplanar interactions are deduced. The high-temperature series expansion (HTSE) combined with the Padé approximants method (PA) is applied to this spinel system to determinate the magnetic phase diagrams, i.e. T cversus dilution x. The critical exponents associated with the magnetic susceptibility (γ) and with the correlation length (ν) are deduced in order phase. © 2010 Springer Science+Business Media, LLC.

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