Skip to main content
Article thumbnail
Location of Repository

Macroscopic optical effects in low concentration ferronematics

By Nina Podoliak, Oleksandr Buchnev, Oleksandr Buluy, Giampaolo D'Alessandro, Malgosia Kaczmarek, Yuriy Reznikov and Timothy J. Sluckin

Abstract

We present a detailed experimental and theoretical study of the optical response of suspensions of ferromagnetic nanoparticles (“ferroparticles”) in nematic liquid crystals (“ferronematics”), concentrating on the magnetic field-induced Frederiks transition. Even extremely low ferroparticle concentrations (at a volume fraction between 2 × 10?5 and 2 × 10?4), induce a significant additional ferronematic linear response at low magnetic field (<100 G) and a decrease in the effective magnetic Frederiks threshold. The experimental results demonstrate that our system has weak ferronematic behavior. The proposed theory takes into account the nematic diamagnetism and assumes that the effective magnetic susceptibility, induced by the nanoparticles, no longer dominates the response. The theory is in good agreement with the experimental data for the lowest concentration suspensions and predicts the main features of the more concentrated ones. The deviations observed in these cases hint at extra effects due to particle aggregation, which we have also observed directly in photograph

Topics: QC
Year: 2011
OAI identifier: oai:eprints.soton.ac.uk:186121
Provided by: e-Prints Soton

Suggested articles

Citations

  1. (2011). 7, 644–649. This journal is ª The Royal Society of Chemistry doi
  2. (1993). The Physics of Liquid Crystals, doi
  3. (2010). Toma sovi cov

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.