High concentration ferronematics in low magnetic fields

TL;DR

This study explores how low magnetic fields influence ferronematics, revealing that initial pretilt and nanoparticle aggregation significantly affect their magneto-optical and dielectric responses, even without bias magnetic fields.

Contribution

It demonstrates that ferronematics can respond to low magnetic fields without bias, highlighting the roles of pretilt and nanoparticle aggregation, which were previously underexplored.

Findings

Low magnetic fields induce detectable responses in ferronematics.

Pretilt and nanoparticle aggregation influence system sensitivity.

Bias magnetic field is not always necessary for response.

Abstract

We investigated experimentally the magneto-optical and dielectric properties of magnetic-nanoparticle-doped nematic liquid crystals (ferronematics). Our studies focus on the effect of the very small orienting bias magnetic field $B_{bias}$, and that of the nematic director pretilt at the boundary surfaces in our systems sensitive to low magnetic fields. Based on the results we assert that $B_{bias}$ is not necessarily required for a detectable response to low magnetic fields, and that the initial pretilt, as well as the aggregation of the nanoparticles play an important (though not yet explored enough) role.