| 1. |
- Benhouria, Y., et al.
(författare)
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Quantum Monte Carlo study of dynamic magnetic properties of nano-graphene
- 2018
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Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 460, s. 223-228
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Tidskriftsartikel (refereegranskat)abstract
- Using the Quantum Monte Carlo simulation (QMCS), the dynamic blocking temperature of a nanographene bilayer has been investigated within the framework of the Transverse Ising Model (TIM) with mixed spins, under the existence of the time-dependent oscillating longitudinal magnetic field (h(t) = h(b) + h(0)cos(omega t)) and the transverse field (Omega). The influence of the time-dependent oscillating longitudinal magnetic field, the period of magnetic field (tau) and the transverse field (Omega) on the thermal behavior of the total longitudinal and transverse dynamic order parameters, the total dynamic magnetic susceptibility and the dynamic hysteresis of the nano-graphene bilayer are also studied. As results, we remark the appearance of multiple hysteresis loops and the system exhibits the superparamagnetic behavior at the dynamic blocking temperature.
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| 2. |
- Bouziani, I., et al.
(författare)
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Magnetoelectronic properties of GaN codoped with (V, Mn) impurities for spintronic devices : Ab-initio and Monte Carlo studies
- 2018
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Ingår i: Physica A. - : ELSEVIER SCIENCE BV. - 0378-4371 .- 1873-2119. ; 512, s. 1249-1259
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we investigate the Magnetoelectronic properties of (V, Mn) codoped GaN using first principles calculations (FPCs) for the spintronic applications. We have obtained the ferromagnetic behavior in (Ga, V)N codoped with Mn atoms, which is believed to be caused by the double exchange mechanism. Moreover, it is observed that our system is halfmetallic at the Fermi level, with 100% spin polarization. The total magnetic moment of (V, Mn) codoped GaN is mainly originated from the V and Mn atoms, and the magnetic moment of V impurities rises with the concentration of V atoms while keeping constant that of the Mn atoms. In addition to that, the exchange coupling is obtained from FPCs and using the Ising model. The Monte Carlo method founded on the Heat Bath algorithm support our FPCs, by investigating the influence of the addition of Mn impurities to (Ga, V)N compound on the critical temperature T-C(MC), the magnetization per site M, the magnetic susceptibility chi and the specific heat C-V. We have found that T-C(MC) is above room temperature as well as the stability of the ferromagnetic state in (Ga, V)N becomes more important after the inclusion of the Manganese.
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| 3. |
- Bouziani, I., et al.
(författare)
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Magnetoelectronic properties of Vanadium impurities co-doped (Cd, Cr)Te compound for spintronic devices : First principles calculations and Monte Carlo simulation
- 2018
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Ingår i: Journal of Magnetism and Magnetic Materials. - : ELSEVIER SCIENCE BV. - 0304-8853 .- 1873-4766. ; 466, s. 420-429
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Tidskriftsartikel (refereegranskat)abstract
- We have applied the first-principles calculations to investigate magnetoelectronic properties of Vanadium impurities co-doped (Cd, Cr)Te compound for spintronic devices. The ferromagnetic (FM) nature in (Cd, Cr)Te compound co-doped with V atoms has been found, and the mechanism responsible for this behavior has been considered to be the double exchange. Moreover, the Curie-temperature calculation reveals that the stability's field of the FM-phase rises with rising both the concentration of Cr and V atoms above ambient temperature. This system presents the half-metallic character where its polarization of spin is total at the Fermi level, and its total magnetic moment is principally induced by Cr and V elements. The spin-orbit coupling (SOC) typically play an important role in the electronic structure calculations due to both the concentration of Cr and V impurities. In addition to that, our results have been confirmed by the calculation of magnetization and susceptibility using the Monte Carlo simulation.
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