Multifunctional materials can exhibit emergent behavior from the coupling of two or more different properties. For example, coupling between magnetic and ferroelectric order enables electrical control of the magnetic state, enabling for example magnetoelectric memory or logic devices that combine the nonvolatility of magnetic order with the energy efficiency of voltage control. Magnetic iron garnets have outstanding magnonic and magnetooptical properties making them valuable in a range of technologies, but they have not been successfully incorporated into thin film two-phase magnetoelectric nanocomposites. Taking advantage of heterogeneously patterned substrates, this work demonstrates the engineering of garnet-perovskite composites in which both phases are polymorphs with the same composition but dramatically different structures and properties. Applying an electric field to the perovskite phase modulates the magnon dispersion and magnetooptical response of the garnet, opening a path to voltage-controlled garnet devices.
@article{arxiv.2604.07495,
title = {Laterally Differentiated Polymorphs: a route to multifunctional nanostructures},
author = {Pete E. Lauer and Kensuke Hayashi and Yuichiro Kunai and Ondřej Wojewoda and Jan Klíma and Ekaterina Pribytova and Michal Urbánek and Aubrey Penn and Takayuki Kikuchi and Renzhi Ma and Takayoshi Sasaki and Takaaki Taniguchi and Caroline A. Ross},
journal= {arXiv preprint arXiv:2604.07495},
year = {2026}
}