Open AccessВлияние слабого сцепления на магнитный переход Фредерикса в ферронематическом жидком кристалле
Author(s) -
В.А. Попов,
В.Г. Гилев,
А.Н. Захлевных
Publication year - 2018
Publication title -
fizika tverdogo tela
Language(s) - English
Resource type - Journals
eISSN - 1726-7498
pISSN - 0367-3294
DOI - 10.21883/ftt.2018.07.46137.364
Subject(s) - fréedericksz transition , liquid crystal , mbba , materials science , suspension (topology) , magnetic nanoparticles , phase diagram , condensed matter physics , crystal (programming language) , coupling (piping) , dielectric , ferrofluid , phase (matter) , magnetic field , nanoparticle , chemistry , nanotechnology , physics , composite material , optoelectronics , computer science , mathematics , organic chemistry , quantum mechanics , homotopy , pure mathematics , programming language
The magnetic Freedericksz transition in a ferronematic representing a diluted suspension of magnetic nanoparticles in an N-(4-methoxybenzylidene)-4-butylaniline (MBBA) nematic liquid crystal was experimentally studied. The transition point was determined by means of dielectric capacitance measurements in cells of different thickness for samples with various volume fractions of ferroparticles. The effect of weak coupling between the magnetic and liquid-crystal subsystems was studied. Low concentrations of quasispherical magnetic particles were shown to decrease the magnetic Freedericksz transition threshold in comparison with a pure liquid crystal. The obtained results were theoretically substantiated. The phase diagram of the suspension was plotted, and the method of estimating the energy of coupling between magnetic particles and a liquid-crystal matrix was proposed.