Institute for Nanomaterials and Nanotechnology

Rabat, Morocco

Institute for Nanomaterials and Nanotechnology

Rabat, Morocco
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Mounkachi O.,Institute for Nanomaterials and Nanotechnology | Salmani E.,Mohammed V University | Boujnah M.,Mohammed V University | Labrim H.,National Center for Energy | And 8 more authors.
Bulletin of Materials Science | Year: 2014

Structural and magnetic properties of Sn0.95Co 0.05O2 nanocrystalline and diluted magnetic semiconductors have been investigated. This sample has been synthesized by co-precipitation route. Study of magnetization hysteresis loop measurements infer that the sample of Sn0.95Co0.05O2 nanoparticle shows a well-defined hysteresis loop at 300 K temperature, which reflects its ferromagnetic behaviour. We confirmed the roomtemperature intrinsic ferromagnetic (FM) semiconductors by ab initio calculation, using the theory of the functional of density (DFT) by employing the method of Korringa-Kohn- Rostoker (KKR) as well as coherent potential approximation (CPA, explain the disorder effect) to systems. The ferromagnetic state energy was calculated and compared with the local-moment-disordered (LMD) state energy for local density approximation (LDA) and LDA-SIC approximation. Mechanism of hybridization and interaction between magnetic ions in Sn0.95Co0.05O 2 is also investigated. To explain the origin of ferromagnetic behaviour, we give information about total and atoms projected density of state functions. © Indian Academy of Sciences.


Mejdoubi A.,Institute for Nanomaterials and Nanotechnology | Mejdoubi A.,Moroccan Foundation for Advanced Science and Innovation and Research MAScIR | Malki M.,Institute for Nanomaterials and Nanotechnology | Malki M.,Moroccan Foundation for Advanced Science and Innovation and Research MAScIR | And 7 more authors.
Journal of Applied Physics | Year: 2011

Three-dimensional finite-difference time-domain simulations are used to study the near- and far-field properties of plasmonic core-shell (CS) nanostructures of reduced symmetry. Special attention is given to silica core and gold shell nanoparticles by changing their geometry. For the simulated range of wavelengths (300-2100 nm) our calculations of the scattering and absorption efficiencies imply strong polarization sensitivity and are highly dependent on the size and geometry of the CS nanostructures. Strong enhancements of the exciting electric field associated with the excitations of nanoparticle plasmons are observed. The wavelength dependence of the scattering spectra and concentration of electromagnetic field in subwavelength volumes have a potential for biosensing and bioimaging. © 2011 American Institute of Physics.


Risite H.,Mohammed V University | Risite H.,Institute for Nanomaterials and Nanotechnology | El Mabrouk K.,Euro-Mediterranean University | Bousmina M.,Euro-Mediterranean University | And 3 more authors.
Journal of Nanoscience and Nanotechnology | Year: 2016

The relationship between the morphological observations and the physical properties of polyamide 11 (PA11)/clay nanocomposites prepared by melt processing was investigated with a special interest on the use of various contents of silane modified PA11 (PA-m-Si). PA-m-Si was prepared using 1 wt% of 3-aminopropyltriethoxysilane (APTES) added to PA11 in reactive extrusion. The morphological observations by TEM and XRD are presented in conjunction with the rheological and mechanical properties of these nanocomposites. The addition of PA-m-Si generated a net favorable interaction with organoclay that permitted higher level of exfoliation/intercalation resulting from a balance of component interactions. XRD spectra of nanocomposites revealed that the increase of PA-m-Si induced a decrease in peak intensities at high clay loadings (≥5 wt%) which informed about a reduction of stacks intercalated structure leading to a higher degree of delamination and a larger increase of aspect ratio of clay. The rheological properties suggest that the extent of a percolation network can be enhanced by increasing the degree of exfoliation/intercalation at fixed clay content. The tensile and thermal properties were also found to be improved in all cases. Copyright © 2016 American Scientific Publishers All rights reserved.


Houmad M.,Mohammed V University | Dakir O.,Mohammed V University | Abbassi A.,Mohammed V University | Benyoussef A.,Mohammed V University | And 4 more authors.
Optik | Year: 2016

Electronic and optical properties of silicon carbide nanosheet (2D monolayer) have been studied using full potential linearized augmented plane wave (FP-LAPW) method with the generalized gradient approximation (GGA) within WIEN2k package. The dielectric tensor is derived within the random phase approximation (RPA). The electronic structure and the optical properties of SiC nanosheet such as the dielectric function, reflectivity, absorption coefficient and optical conductivity are calculated for both perpendicular and parallel electric field polarizations. © 2015 Elsevier GmbH.


Risite H.,Mohammed V University | Risite H.,Institute for Nanomaterials and Nanotechnology | Mabrouk K.E.L.,Euro-Mediterranean University | Bousmina M.,Euro-Mediterranean University | And 3 more authors.
Journal of Nanoscience and Nanotechnology | Year: 2016

Polyamide-11 (PA11)/organoclay nanocomposites were prepared via melt compounding using silane grafted montmorillonites and Cloisite 20 A. Two graft procedures were used for clay modification. The first one provided a grafted 3-aminopropyltriethoxysilane (APTES) at clay surfaces, whereas the second led to intercalated structure in addition to grafted APTES at clay surface. X-ray diffraction and transmission electron microscopy confirmed the formation of the exfoliated nanocomposites at low clay loading (2 wt%) and a mixture of exfoliated and intercalated structures at higher clay contents. Thermogravimetric analysis, melt rheology as well as tensile tests showed that the degree of dispersion of clay within polymer matrix plays a vital role in property improvement. In addition, elongation at break was considerably enhanced in the case of silane grafted clay. This was attributed to hydrogen bonding between clay surfaces and PA11 via APTES. Copyright © 2016 American Scientific Publishers All rights reserved.


Houmad M.,Mohammed V University | Zaari H.,Mohammed V University | Benyoussef A.,Mohammed V University | Benyoussef A.,Institute for Nanomaterials and Nanotechnology | And 3 more authors.
Carbon | Year: 2015

The linear optical and electronic properties of a monolayer graphene sheet are investigated using the Density Functional Theory within the Full Potential Linearized Augmented Plane Wave (FP-LAPW) formalism. Three approaches are used in this work: The Generalized Gradient Approximation (GGA), the Tran-Blaha modified Becke-Johnson exchange potential approximation (TB-mBJ); implemented in WIEN2K code; and GW (Green function G and screened Coulomb interaction W) implemented in Yambo code. The band gap of graphene with and without silicon doping and the effect of silicon on optical properties of graphene are calculated. The silicon doping opens the band gap of graphene and increases its optical conductivity. This material may be used in solar cell application. Other optical properties such as reflectivity and refractive index are also studied. © 2015 Elsevier Ltd. All rights reserved.


Abbassi A.,Mohammed V University | Ez-Zahraouy H.,Mohammed V University | Benyoussef A.,Mohammed V University | Benyoussef A.,Institute for Nanomaterials and Nanotechnology
Optical and Quantum Electronics | Year: 2015

Optical properties of ZnO doped with Silicon and Aluminum were studied by first principle calculations using the density functional theory. The optical absorption, transmittance and optical constants are investigated using the full potential-linearized augmented plane wave method with the generalized gradient approximation and mBJ approximation, implemented in Wien2k package. With the mBJ approximation the direct optical gap of a pure ZnO is about 3.34 eV, which is in good agreement with experimental results. The behavior of the transmittance and the absorption of the Al-doped ZnO are higher and better than those of the Si-doped ZnO. The transmittance of Al-doped ZnO is stable and high in the visible light range and can reach 96 % at 400 nm. This confirms the physical characteristics that can present Al to be used as suitable transparent material electrodes in solar cells. © 2014, Springer Science+Business Media New York.


Salmani E.,Mohammed V University | Mounkachi O.,Institute for Nanomaterials and Nanotechnology | Ez-Zahraouy H.,Mohammed V University | Hamedoun M.,Institute for Nanomaterials and Nanotechnology | And 2 more authors.
Journal of Superconductivity and Novel Magnetism | Year: 2013

Based on first-principles spin-density functional calculations, the optical and magnetic properties of Mn-doped ZnO diluted magnetic semiconductors with acceptor defects by Zn vacancies (VZn) are studied, using the Korringa-Kohn-Rostoker method (KKR) combined with the coherent potential approximation (CPA). Ferromagnetic and half-metallic behaviors were observed and confirmed with the local-moment-disordered (LMD) state energy for local density approximation (LDA) and local density approximation-self-interaction correction (LDA-SIC). The mechanism of hybridization and the interaction between magnetic ions in P-type (Zn, Mn)O are also investigated. Moreover, the optical absorption spectra obtained by ab-initio calculations confirm the ferromagnetic stability based on the charge state of magnetic impurities. © 2012 Springer Science+Business Media, LLC.

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