Effect of magnetic nanoparticles on the nematic-smectic-A phase transition
Abstract
Recent experiments on mixed liquid crystals have highlighted the hugely significant role of ferromagnetic nanoparticle impurities in defining the nematic-smectic-A phase transition point. Structured around a Flory-Huggins free energy of isotropic mixing and Landau-de Gennes free energy, this article presents a phenomenological mean-field model that quantifies the role of such impurities in analyzing thermodynamic phases, in a mixture of thermotropic smectic liquid crystal and ferromagnetic nanoparticles. First we discuss the impact of ferromagnetic nanoparticles on the isotropic-ferronematic and ferronematic-ferrosmectic phase transitions and their transition temperatures. This is followed by analysis of various topologies in the phase diagrams. Our model results indicate that there exists a critical concentration of nanoparticle impurities for which the second order N-SmA transition becomes first order at a tricritical point. Calculations based on this model show remarkable agreement with experiment.
Keywords
Cite
@article{arxiv.1705.08702,
title = {Effect of magnetic nanoparticles on the nematic-smectic-A phase transition},
author = {Prabir K Mukherjee and Amit K Chattopadhyay},
journal= {arXiv preprint arXiv:1705.08702},
year = {2017}
}
Comments
14 pages, 5 figures