Nanocomposites of ferroelectric liquid crystals and FeCo nanoparticles: towards a magnetic response via the application of a small electric field

ABSTRACT

We study a nanocomposite consisting of a ferroelectric liquid crystal and a magnetic nanoparticle in order to explore the possibility of using it as a magnetic resonant imaging contrast agent which will measure a field of 20 V/m. To achieve this we use the ferroic properties exhibited by the nanocomposite. We used the ferroelectric liquid crystal 2-(4-((2-fluorooctyl)oxy)phenyl)-5-(octyloxy)pyrimidine mixed with FeCo nanoparticles nominally 2–3 nm in diameter in concentrations of 0.56, 4.3 and 10.8 wt%. The 10.8 wt% sample was chosen for our study because the nanoparticles acted as a lubricant for the ferroelectric liquid crystal. This concentration yields nanoparticle clusters in about 5 − 10 μm diameter spherulites. An electric field as low as 5V/cm is enough to turn and realign the spherulites where the particles are contained. We estimate the value of the magnetic in a spehrulite and associate it to the number of spherulites aligned as a function of electric field. We find thus that we can achieve low electric fields.

Graphical Abstract

KEYWORDS:

• Nanocomposites
• ferroelectric liquid crystals
• magnetic nanoparticles
• electric field effects

Acknowledgments

P. Romero Hasler acknowledges CONICYT scholarship 21130413 for doctoral studies. E. A. Soto-Bustamante thanks FONDECYT Project 1130187. L. J. Martínez-Miranda thanks partial support by a Fulbright Scholarship, supported by the Institute of International Education/Council for International Exchange of Scholars and by the Comisión para el Intercambio Educativo entre Chile y los Estados Unidos de América.

We thank Dr. W. Haase for useful insights into the nature of the ferroelectric-nanoparticle interaction, and Dr. M. Wuttig for discussions on the magnetic field.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Consejo Nacional de Investigaciones Científicas y Técnicas [21130413];Fondo Nacional de Desarrollo Científico y Tecnológico [1130187];Fulbright Chile-USA;