Ferronematics in confinement

TL;DR

This paper numerically investigates the hysteresis and magnetization switching mechanisms of ferronematic slabs under external magnetic fields, revealing how wall conditions influence reversible magnetization control.

Contribution

It introduces a numerical approach to analyze hysteresis and identifies two distinct magnetization switching mechanisms in ferronematics, highlighting the role of wall interactions.

Findings

Critical magnetic field strength depends on system parameters.

Two mechanisms of magnetization switching are characterized.

Walls can be engineered to enable reversible magnetization control.

Abstract

The behavior of a uniformly magnetized ferronematic slab is investigated numerically in a situation in which an external magnetic field is applied parallel and antiparallel, respectively, to its initial magnetization direction. The employed numerical method allows one to determine hysteresis curves, from which a critical magnetic field strength (i.e., the one at which the ferronematic sample becomes distorted) as function of the system parameters can be inferred. Two possible mechanisms of switching the magnetization by applying a magnetic field in the antiparallel direction are observed and characterized in terms of the coupling constant between the magnetization and the nematic director as well as in terms of the coupling strength of the nematic liquid crystal and the walls of the slab. Suitably prepared walls allow one to combine both switching mechanisms in one setup, such that one can construct a cell the magnetization of which can be reversibly switched off.