Magnetic-Field Induced Isotropic to Nematic Phase Transition in Ferronematics

Abstract

In this work the thermotropic liquid crystal 4-(trans-4'-n-hexylcyclohexyl)-isothiocyanato-benzene (6CHBT) was doped with differently shaped magnetic nanoparticles with the aim to increase the sensitivity of the liquid crystal on the external magnetic field. The volume concentration of the magnetic particles was 2×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> . The phase transition temperature from isotropic to nematic phase in external magnetic fields up to 12 T was monitored by precise capacitance measurements in capacitance cells filled with the prepared ferronematic samples. The shift in the temperature from isotropic to nematic phase was observed in the liquid crystal doped with rodlike particles. To our knowledge, this is the first observation of such a magnetic-field induced transition in ferronematics based on a calamitic liquid crystal.