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.