Polarization enhancement in Fe doped BNT based relaxors using Bi compensation

Abstract Pseudocubic structural BNT-BT-BST based ergodic relaxors are investigated through Bi3+ and Fe3+ modulation in A and B sites of perovskite. High recoverable energy storage density and efficiency with excellent thermal stability, and large electrostrictive strain (0.24%) with ultralow hysteresis (2.8%) are achieved under a relatively low electric field. Slim polarization hysteresis (P-E) loops and strain curves are attributed to the absence of long-range ferroelectric domain as the introduction of BST. The incremental dopants that can restrain oxygen vacancies induced by A-site cationic vacancy ( V A ′ ′ ), will promote polarization, strengthen relaxor characteristics and suppress the reduction of Ti4+. A detailed mechanism of relaxor-ferroelectric phase transition and defect dipole of ( Fe Ti ′ − V O • • )• on polarization and electrostrictive strain is discussed. The work provides a new route in designing low-hysteresis BNT based relaxors for practical energy storage and actuator applications.