Heat-mediated magnetoelectric effect in a magnetic nanoparticle - pyroelectric polymer composite

Most magnetoelectric composites are engineered through a strain-mediated approach in which a piezoelectric material is intimately coupled with a magnetostrictive material. In these composites, a change of electrical polarization in the piezoelectrics is accomplished through the deformation of the magnetostrictive material under a magnetic field. While this approach is successful and has enabled many applications, it may become inappropriate if the composite is developed for biomedical applications, as most magnetostrictive materials usually have poor biocompatibility. Here, we demonstrate an alternative magnetoelectric mechanism based on nanostructured composites of magnetic and pyroelectric materials. In this approach, the heat generated by magnetic nanoparticles under a high-frequency alternating magnetic field induces the depolarization of a pyroelectric matrix, resulting in an electrical output signal. Because the depolarization is reversible, the process can be repeated by pulsing the alternating magnetic field, with the composite acting as a current source. This heat-coupled approach allows for new combinations of more biocompatible materials to reach the magnetoelectric effect, paving the way for the application of magnetoelectric materials in the biomedical field.