• • Increasing vortex core density from 6 to 27 μm⁻² enhances dielectric constant (ε33/ε0) and piezoelectric coefficient (d33) by ~3.5-fold and ~3.4-fold, respectively, as shown by phase-field simulations. This quantitative link provides a design rule for engineering high-performance piezoelectrics via topological domain control.
• • Mechanically assisted direct-current poling (MDCP) raises vortex core density from 0.01 to 21 μm⁻² in bulk PMN-30PT crystals, yielding d33 of 1820 pC·N⁻¹ (from 1380 pC·N⁻¹) and ε33/ε0 of 6,230 (from 4,630). These enhancements exceed typical gains from conventional composition or phase-boundary engineering, offering a scalable route for device optimization.
• • Vortex cores exhibit localized elastic strain and a flattened energy landscape that reduces the energetic cost of polarization rotation, facilitating enhanced electromechanical response. This mesoscale mechanism operates without nanoscale confinement, enabling application in bulk three-dimensional crystals.
• • The MDCP strategy enables controllable manipulation of topological domain architectures, achieving a 2100-fold increase in vortex core density. This demonstrates a practical pathway for industrial-scale production of high-performance ferroelectric materials for sensors, actuators, and transducers.