| 1. |
- Benhouria, Y., et al.
(author)
-
Dynamic Magnetic Properties of a Mixed Spin Ising Double-Walled Ferromagnetic Nanotubes : A Dynamic Monte Carlo Study
- 2017
-
In: Journal of Superconductivity and Novel Magnetism. - : Springer Science and Business Media LLC. - 1557-1939 .- 1557-1947. ; 30:3, s. 839-844
-
Journal article (peer-reviewed)abstract
- Using the dynamic Monte Carlo simulation, the dynamic critical temperature of a ferromagnetic or ferrimagnetic double-walled nanotubes (DWNTs) is studied within the kinetic Ising model under the presence of a time-dependent oscillating external magnetic and crystal fields with mixed spins S (A) = 1 and S (B) = 3/2. The effects of the time-dependent oscillating external magnetic field, the period of the oscillating magnetic field, and the crystal field on the thermal behavior of the dynamic sub-lattice order parameters and the total dynamic order parameter, total dynamical magnetic susceptibility, dynamical specific heat, and dynamic hysteresis of a DWNTs are studied. Our theoretical predictions may be a reference for future experiment studies of the nanostructures.
|
|
| 2. |
- Benhouria, Y., et al.
(author)
-
Monte Carlo simulation of dielectric properties of a mixed spin-3/2 and spin-5/2 Ising ferrielectric nanowires
- 2017
-
In: Ferroelectrics (Print). - : TAYLOR & FRANCIS LTD. - 0015-0193 .- 1563-5112. ; 507:1, s. 58-68
-
Journal article (peer-reviewed)abstract
- Dielectric properties of Ising ferrielectric nanowires with spin-3/2 core and spin-5/2 shell structure are systematically studied by the use of the Monte Carlo simulation in the presence of the external longitudinal electric field. Special focus is given to the effects of the core and shell interactions, the interface coupling and the temperature on the core and shell polarizations, the specific heat, the compensations points, the susceptibility and hysteresis behaviors. Some characteristic behaviors are found, such as the existence of triple hysteresis loops for appropriate values of the system parameters affected by the antiferroelectric interface coupling constant and the temperature. The results are compared with those of recently published works and a qualitatively good agreement is found.
|
|
| 3. |
- Bouhou, S., et al.
(author)
-
Some hysteresis loop features of 2D magnetic spin-1 Ising nanoparticle : shape lattice and single-ion anisotropy effects
- 2017
-
In: Zhongguó wùli xuékan. - : Elsevier BV. - 0577-9073. ; 55:6, s. 2224-2235
-
Journal article (peer-reviewed)abstract
- The effects of longitudinal and transverse crystal-fields on the magnetic hysteresis behaviors of 2D spin-1 Ising nanoparticles are investigated, by using the effective-field theory based on the probability distribution technique with correlations. Nanoparticles with hexagonal or square lattice are studied. A number of characteristic phenomena such as triple and quadruple hysteresis loop behaviors have been observed for certain physical parameters, originating from the competitions among the core/shell exchange interaction, anisotropies, temperature and the longitudinal magnetic field. Finally, the obtained results are compared with some experimental and theoretical results.
|
|
| 4. |
- Chafai, A., et al.
(author)
-
Shallow donor inside core/shell spherical nanodot : Effect of nanostructure size and dielectric environment on energy spectrum
- 2017
-
In: Superlattices and Microstructures. - : Elsevier BV. - 0749-6036 .- 1096-3677. ; 111, s. 976-982
-
Journal article (peer-reviewed)abstract
- We have reported the impact of the core and shell radii on the energy spectrum of centered shallow donor confined inside CdSe/ZnTe core/shell quantum dot and ZnTe/CdSe inverted core/shell quantum dot. The dielectric discontinuity between the nanosystems and their surrounding medium was considered. In order to examine the behavior of the donor binding energy as a function of the spatial parameters a variational approach within the framework of the effective-mass approximation was deployed. Our model shows that for a fixed shell radius the increase of the core radius value blue-shifts the binding energy of the donor inside inverted core/shell quantum dot only if the value of the core to shell radii ratio is between 0.9 and 1, otherwise it is red-shifted. By contrast, for core/shell quantum dot system the binding energy is red-shifted by increasing the core radius for a fixed nanostructure size and for all values of the core to shell radii ratio. We have also found that the donor binding energy values are more important in a core/shell nanodot than in an inverted core/shell quantum dot.
|
|
| 5. |
- Chafai, A., et al.
(author)
-
Tuning the binding energy of on-center donor in CdSe/ZnTe core/shell quantum dot by spatial parameters and magnetic field strength
- 2017
-
In: Physica. E, Low-Dimensional systems and nanostructures. - : Elsevier BV. - 1386-9477 .- 1873-1759. ; 94, s. 96-99
-
Journal article (peer-reviewed)abstract
- The behavior of the electron ground state and of the ground state binding energy of an on-center donor confined in a CdSe/ZnTe core/shell spherical nanodot was examined theoretically within the framework of the effectivemass approximation and using a variational calculation. The radial dependence of the dielectric constant and of the electron effective mass as well as the effect of the polarization charge were considered. Our results highlight the large impact of the magnetic field strength and the spatial parameters on the energy behavior for both the electron and the donor. Our study points out also the fact that the magnetic confinement may be eclipsed by the spatial confinement in heteronanostructures with small size and expected to be dominant in the opposite case.
|
|
| 6. |
- El Hamri, M., et al.
(author)
-
Hysteresis loop behaviors of a decorated double-walled cubic nanotube
- 2017
-
In: Physica. B, Condensed matter. - : Elsevier BV. - 0921-4526 .- 1873-2135. ; 524, s. 137-143
-
Journal article (peer-reviewed)abstract
- The effect of surface shell parameters on the hysteresis loop behaviors of a decorated Ising cubic nanotube, consisting of a ferromagnetic spin-12 core which is interacting ferrimagnetically with a ferromagnetic spin-1 surface shell, is investigated, in the present work, within the effective-field theory with correlations based on the probability distribution technique. We have found that these parameters have a strong effect on the shape and the number of hysteresis loops and also on the coercive field and remanent magnetization behaviors. Indeed, triple, quintuple, septuple and nonuple hysteresis loop patterns have also been observed.
|
|
| 7. |
- El Hamri, M., et al.
(author)
-
Magnetic behaviors of a transverse spin-1/2 Ising cubic nanowire with core/shell structure
- 2017
-
In: Physica. B, Condensed matter. - : Elsevier. - 0921-4526 .- 1873-2135. ; 507, s. 51-60
-
Journal article (peer-reviewed)abstract
- The surface shell exchange coupling effect on the magnetic properties (surface shell, core, total longitudinal and total transverse magnetizations, susceptibility, phase diagram and hysteresis loops) of a transverse spin-1/2 Ising cubic nanowire is investigated, in the present work, by employing the effective-field theory based on the probability distribution technique with correlations, for both ferro-and antiferromagnetic cases. We have found that this parameter has a strong effect on the magnetic properties in both cases. In the ferromagnetic case, the total longitudinal magnetization curves display Q-and S-type behaviors and the hysteresis loop has just one loop, whereas in the antiferromagnetic case, the N-type behavior, in which one compensation temperature appears below the critical temperature, exists in the total longitudinal magnetization curve versus reduced temperature, and triple hysteresis loops are found. The effect of applied field is also investigated on the total longitudinal magnetization for the both cases, and we have found that a large applied field value can overcome the antiferromagnetic coupling leading to a ferromagnetic-like behavior.
|
|
| 8. |
- El Hamri, M., et al.
(author)
-
Magnetic Properties of a Diluted Transverse Spin-1 Ising Nanocube with a Longitudinal Crystal-Field
- 2017
-
In: INTERNATIONAL SYMPOSIUM ON CLUSTERS AND NANOMATERIALS. - : SPIE-INT SOC OPTICAL ENGINEERING. - 9781510608429
-
Conference paper (peer-reviewed)abstract
- In the present work, the effective field theory with correlations based on the probability distribution technique has been used to investigate the effect of the surface shell longitudinal cristal field on the magnetic properties of a diluted antiferromagnetic spin-1 Ising nanocube particle. This effect has also been studied on the hysteresis loops of the system. It is found that this parameter has a strong effect on the magnetization profiles, compensation temperature, coercive field and remanent magnetization.
|
|
| 9. |
- El Hamri, M., et al.
(author)
-
Reentrant phenomenon in a transverse spin-1 Ising nanoparticle with diluted magnetic sites
- 2017
-
In: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 442, s. 53-61
-
Journal article (peer-reviewed)abstract
- In the present work, we have examined the influence of surface shell exchange coupling on the magnetic properties of a diluted ferromagnetic spin- 1 Ising nanocubic particle, by employing the effective-field theory with correlations based on the probability distribution technique. Some interesting results have been found such as, a tricritical point, a triple point, an isolated critical point, reentrant and even double reentrant phenomena, S-, R- and Q-type behaviors, as well as, both first-and second-order phase transitions as it is confirmed by the free energy. In addition, when the interactions are low between the surface shell sites, quadruple hysteresis loops can be seen in the system.
|
|
| 10. |
- Htoutou, K., et al.
(author)
-
The Magnetic Properties of the Mixed Ferrimagnetic Ising System with Random Crystal Field
- 2017
-
In: Journal of Superconductivity and Novel Magnetism. - : SPRINGER. - 1557-1939 .- 1557-1947. ; 30:5, s. 1247-1256
-
Journal article (peer-reviewed)abstract
- Using the effective-field theory EFT based on the probability distribution technique, the effect of the random crystal field on the magnetic properties of ferrimagnetic mixed Ising system with both spin-1 and spin-3/2 is investigated. The critical temperature is discussed as function of different strengths of the random crystal field and the exchange interactions. The phase diagrams are calculated numerically for a square lattice and the number of characteristic phenomena, such as the tricritical point are found. Our results are different to that reported in Souza et al. (Physica A 444, 589-600 2016).
|
|
