Giant Thermally Induced Magnetoelectric Effect in FeRh-Based Core–Shell Nanoparticles

Here, we propose a concept for a giant thermally induced magnetoelectric (ME) effect in core–shell nanoparticles based on the first-order magnetoelastic phase transition in an FeRh alloy. ME nanoparticles are promising for nanoscale actuation and biomedical applications, yet their performance is strongly limited by the small magnetostrictive strain of conventional magnetic materials. The antiferromagnetic–ferromagnetic transition in FeRh is accompanied by a reversible volume change of about 1%, which is two orders of magnitude larger than typical magnetostriction. Finite-element modeling of FeRh@BaTiO₃ and FeRh@PVDF nanoparticles shows that this volume change can generate electric potentials up to ∼80 mV, exceeding the response of conventional Fe₃O₄-based ME nanoparticles by more than two orders of magnitude. The proposed concept circumvents the intrinsic strain limit of magnetostriction and opens a route toward high-amplitude, remotely addressable nanoscale actuators for biomedical and microrobotic applications.