Increasing the magnetic sensitivity of liquid crystals by rod-like magnetic nanoparticles

P. Kopċanský¹ - N. Tomašoviċová¹ - T. Tóth-Katona² - N. Éber² - M. Timko¹ - V. Závišová¹ - J. Majorošová¹ - M. Rajňak¹ - J. Jadzyn³ - X. Chaud⁴

¹ Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Košice, Slovakia
² Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, H-1525 Budapest, P.O.Box 49, Hungary
³ Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60179 Poznan, Poland
⁴ High Magnetic Field Laboratory, CNRS, 25 Avenue des Martyrs, Grenoble, France

Abstract
Magnetic Fréedericksz transition was studied in ferronematics based on the nematic liquid crystal 4-(trans-4'-n-hexylcyclohexyl)-isothiocyanatobenzene (6CHBT). 6CHBT was doped with rod-like magnetic particles of different size and volume concentration. The volume concentrations of magnetic particles in the prepared ferronematics were φ₁=10⁻⁴ and φ₂=10⁻³. Structural changes were observed by capacitance measurements, which evidenced of a significant influence of the concentration, shape anisotropy and/or the size of the magnetic particles on the magnetic response of these ferronematics. Tables 1, Figs 3, Refs 14.