Hydrophobic-Phase Deposition of Barium Titanate on Cobalt Ferrite nanoparticles from a bimetallic complex precursor for the synthesis of magnetoelectric core-shell materials

We report a novel deposition pathway for barium titanate (BTO) onto hydrophobically coated cobalt ferrite (CFO) nanoparticles, resulting in the formation of magnetoelectric core-shell nanoparticles. Our strategy utilizes a bimetallic Ba and Ti oleate (BTOle) precursor, which hydrophobically interacts with dimethyldioctadecylammonium bromide (DDAB)- stabilized CFO particles during an interfacial phase transfer step. Thermal post-treatment yields a crystalline structure comprising distinguishable BTO and CFO phases, with BTO adopting a distorted cubic to tetragonal crystal phase. Magnetoelectric characterization yields a millivolt voltage-range output, associated with the mechanical coupling between the piezoelectric and magnetostrictive phases. This method circumvents traditional sol-gel limitations and phase transfer hurdles, offering a streamlined route for fabricating magnetoelectric nanoparticles. Our results suggest magnetoelectric particles are suitable for incorporation in wireless actuation technologies.