Magnetic segregation effect in liquid crystals doped with carbon nanotubes

• Danil A. Petrov,
• Pavel K. Skokov,
• Alexander N. Zakhlevnykh and
• Dmitriy V. Makarov

Beilstein J. Nanotechnol. 2019, 10, 1464–1474, doi:10.3762/bjnano.10.145

• physics of ferronematics and ferrocholesterics (magnetic suspensions of ferromagnetic nanoparticles in LCs) is called the magnetic segregation effect [12]. It has a significant influence on the type of orientation transitions in LC composite materials [40][41][42][43][44], and, as predicted in [39], must

• comparison in Figure 4 and Figure 5. Qualitative differences in the behavior of φ(ζ) and ψ(ζ) should be expected at σ ≃ σm, where the appearance of the homeotropic phase is not prohibited, which can lead to reentrant orientational transitions. For example, in ferronematics (suspensions of anisometric

Magnetic field induced orientational transitions in liquid crystals doped with carbon nanotubes

• Danil A. Petrov,
• Pavel K. Skokov and
• Alexander N. Zakhlevnykh

Beilstein J. Nanotechnol. 2017, 8, 2807–2817, doi:10.3762/bjnano.8.280

• ferronematics have been published [4][5], which indicates the interest in this kind of composite materials. Along with ferri- or ferromagnetic particles it is also possible to use carbon nanotubes (CNTs) in order to increase the magneto-orientational response of the LC matrix [6][7]. Due to the highly elongated

• segregation effect [3] in the physics of ferronematics. This means that CNTs migrate to those regions of the layer where their magnetic energy in the field () and the orientational energy in the LC matrix () are minimal. Orientational phases of the suspension The system of Equations 5–8 allows for uniform

• dipole (ferromagnetic) and quadrupole (diamagnetic) particles in LC suspensions. In the present paper we consider a physical system that, unlike ferronematics, does not have a dipole response to the applied magnetic field. We study LC suspensions with anisometric diamagnetic particles. Thus, the present

Ferrocholesteric–ferronematic transitions induced by shear flow and magnetic field

• Dmitriy V. Makarov,
• Alexander A. Novikov and
• Alexander N. Zakhlevnykh

Beilstein J. Nanotechnol. 2017, 8, 2552–2561, doi:10.3762/bjnano.8.255

• to a “smoothing” of the magnetic field-induced transitions in ferronematics. In FCs the possibility of controlling the spiral structure and its unwinding by a combined action of a magnetic field and a shear flow has not been studied. This problem is being investigated in the present paper. Basic

Alternating current magnetic susceptibility of a ferronematic

• Natália Tomašovičová,
• Jozef Kováč,
• Veronika Gdovinová,
• Nándor Éber,
• Tibor Tóth-Katona,
• Jan Jadżyn and
• Peter Kopčanský

Beilstein J. Nanotechnol. 2017, 8, 2515–2520, doi:10.3762/bjnano.8.251

• saturation can be increased by about two orders of magnitude. This finding paves a way to application possibilities, such as low magnetic field sensors, or basic logical elements for information storage. Keywords: ac magnetic susceptibility; ferronematics; magnetic particles; Introduction The great

• susceptibility anisotropy (χa ≈ 10−6) of liquid crystals. As a way of lowering the required applied magnetic field, doping liquid crystals with magnetic nanoparticles (MNPs) has been proposed [2]. The stable colloidal suspensions of MNPs in nematic LCs are now known as ferronematics (FNs). Following the first

• implementation of ferronematics [3], they soon have become favourite targets for research. Several theoretical models have been developed by extending the Ericksen–Leslie continuum theory [4][5][6], or the hydrodynamic description [1][7][8] for taking into account the interactions between MNPs, the host liquid