High energy storage characteristics in Bi6-xLaxMgTi4O18 films

Bi6-xLaxMgTi4O18 films were prepared by the sol-gel method combined with layer-by-layer plasma treatment. The incorporation of La3+ ions weakens intrinsic inter-domain interactions, enhances both the defect dipole moment and its activity, and concurrently refines grain size while improving grain insulation. A synergistic enhancement of polarization intensity, breakdown strength, and relaxor ferroelectric behavior enabled a high energy storage density and efficiency. The Bi4.75La1.25MgTi4O18 film achieved an energy storage density of 97.0 J/cm3 and energy storage efficiency of 87%. A synergistic strategy leveraging defect dipoles and refined grain size effectively enhances energy storage performance, providing a promising avenue for the design of high-performance dielectric capacitors.