Synthetic magnetoelectric coupling in a nanocomposite multiferroic

摘要

Given the paucity of single phase multiferroic materials (with largeferromagnetic moment), composite systems seem an attractive solution in thequest to realize magnetoelectric cou-pling between ferromagnetic andferroelectric order parameters. Despite having antiferro-magnetic order, BiFeO3(BFO) has nevertheless been a key material in this quest due to excel-lentferroelectric properties at room temperature. We studied a superlatticecomposed of 8 repetitions of 6 unit cells of La0.7Sr0.3MnO3 (LSMO) grown on 5unit cells of BFO. Significant net uncompensated magnetization in BFO isdemonstrated using polarized neutron reflectometry in an insulatingsuperlattice. Remarkably, the magnetization enables magnetic field to changethe dielectric properties of the superlattice, which we cite as an example ofsynthetic magnetoelectric coupling. Importantly, this controlled creation ofmagnetic moment in BFO suggests a much needed path forward for the design andimplementation of integrated oxide devices for next generation magnetoelectricdata storage platforms.