Факультет електроніки та інформаційних технологій (ЕлІТ)
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Item Directed transport of suspended ferromagnetic nanoparticles under both gradient and uniform magnetic fields(IOP Publishing, 2020) Денисов, Станіслав Іванович; Денисов, Станислав Иванович; Denysov, Stanislav Ivanovych; Лютий, Тарас Володимирович; Лютый, Тарас Владимирович; Liutyi, Taras Volodymyrovych; Павлюк, Максим Олександрович; Павлюк, Максим Александрович; Pavliuk, Maksym OleksandrovychThe suspended ferromagnetic particles subjected to the gradient and uniform magnetic fields experience both the translational force generated by the field gradient and the rotational torque generated by the fields strengths. Although the uniform field does not contribute to the force, it nevertheless influences the translational motion of these particles. This occurs because the translational force depends on the direction of the particle magnetization, which in turn depends on the fields strengths. To study this influence, a minimal set of equations describing the coupled translational and rotational motions of nanosized ferromagnetic particles is introduced and solved in the low Reynolds number approximation. Trajectory analysis reveals that, depending on the initial positions of nanoparticles, there exist four regimes of their directed transport. The intervals of initial positions that correspond to different dynamical regimes are determined, their dependence on the uniform magnetic field is established, and strong impact of this field on the directed transport is demonstrated. The ability and efficiency of the uniform magnetic field to control the separation of suspended ferromagnetic nanoparticles is also discussed.Item Temperature Dependence of the Drift Velocity of Ferromagnetic Nanoparticles in Viscous Fluids(Sumy State University, 2018) Денисов, Станіслав Іванович; Денисов, Станислав Иванович; Denysov, Stanislav Ivanovych; Yermolenko, A.S.; Bosenko, V.S.In Refs. [1, 2], the deterministic theory of drift of single-domain ferromagnetic nanoparticles in viscous fluids, which occurs due to the Magnus effect, has recently been developed and numerically confirmed. Here, we present analytical and numerical results obtained within the stochastic theory on the influence of temperature on the drift velocity.Item Minimal Set of Equations for Drift of Ferromagnetic Nanoparticles Induced by Magnetic Fields in Fluids(Sumy State University, 2018) Денисов, Станіслав Іванович; Денисов, Станислав Иванович; Denysov, Stanislav Ivanovych; Лютий, Тарас Володимирович; Лютый, Тарас Владимирович; Liutyi, Taras Volodymyrovych; Kvasnina, O.V.; Yermolenko, A.S.Recently, it has been established that ferromagnetic nanoparticles subjected to a periodic force and a non-uniformly rotating magnetic field can drift in a viscous fluid due to the Magnus effect. Because the drift phenomenon is of interest for applications such as particle separation, in this work we present a minimal set of equations for describing this phenomenon when a periodic force is induced by a gradient magnetic field.Item Influence of the inverse faraday effect on switching and oscillations of magnetization in single-domain nanoparticles(Sumy State University, 2011) Kukharev, A.V.; Daniluyk, A.L.We have performed a numerical simulation of magnetization switching and oscillations in a ferromagnetic single-domain particle in the disk form under the influence of nanosecond laser pulses with linearly and circularly polarization. During the simulation of magnetization we have used the macrospin approximation with the generalized Landau-Lifshitz-Gilbert equation. In this model the interaction of laser with ferromagnetic metal leads to following processes: a change in energy magnetic crystallographicanisotropy and in a value of saturation magnetization, a generation of the spin-polarized current by photon pressure, an occurrence of the magnetic field induced by the magnetoopticalinverse Faraday effect in the case of circularly polarized laser. The analysis has shown that the interaction of laser pulses with a ferromagnetic nanodisk leads to change in the direction of its magnetization. This process is accompanied by magnetization oscillations with duration from units to tens of nanoseconds. As it follows from the obtained results, the main cause of magnetization switching is the reduction of magnetic anisotropy energy at heating of the structure by laser. The field of the inverse Faraday effect can lead to an increase in frequency and amplitude of this oscillations. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/20648