Alternating current magnetic susceptibility of a ferronematic

• Main Authors: Natália Tomašovičová, Jozef Kováč, Veronika Gdovinová, Nándor Éber, Tibor Tóth-Katona, Jan Jadżyn, Peter Kopčanský
• Format: Article
• Language: English
• Published: Beilstein-Institut 2017-11-01
• Series: Beilstein Journal of Nanotechnology
• Subjects: ac magnetic susceptibility; ferronematics; magnetic particles
• Online Access: https://doi.org/10.3762/bjnano.8.251

We report on experimental studies focusing on the dynamic ac magnetic susceptibility of a ferronematic. It has been shown recently, that in the isotropic phase of a ferronematic, a weak dc bias magnetic field of a few oersteds increases the ac magnetic susceptibility. This increment vanishes irreversibly if the substance is cooled down to the nematic phase, but can be reinduced by applying the dc bias field again in the isotropic phase [Tomašovičová, N. et al. Soft Matter 2016, 12, 5780–5786]. The effect has no analogue in the neat host liquid crystal. Here, we demonstrate that by doubling the concentration of the magnetic nanoparticles, the range of the dc bias magnetic field to which the ferronematic is sensitive without 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.