Hybrid Magneto-Electric Materials for Sensing of Weak Electric Field Using Magnetic-Resonance Imaging

We study magneto-electric (ME) coupling mechanisms in two systems, namely ferromagnetic (FM) particles dispersed in a liquid crystal (LC) and hybrid ferroelectric (FE)–FM grains. The ME effect may appear in these systems due to the rotation of nanoparticles under the action of electric and magnetic fields. We show that a high sensitivity to the applied electric field can be achieved in both LC/magnetic particles system and hybrid FE–FM particles. In particular, even the electric field of 10 V/m essentially influences the magnetic state of these materials for proper geometric parameters. At that magnetic state, these systems can be measured in magnetic-resonance imaging (MRI) experiments. We show that MRI contrast changes up to 10% in a weak electric field. These systems can be used as MRI contrast agents for studying electrical activity in a human body.