Electromechanical hardening of Na1/2Bi1/2TiO3-based ceramics by the in-situ formed secondary phase

One of the primary challenges in high-power devices is the issue of heating, which is caused by energy loss resulting from domain wall motion. To address this problem, our study established a electromechanical hardening approach by integrating NiO into Na1/2Bi1/2TiO3 (NBT). This method leads to the in-situ formation of the second phase within grains and between the grain boundaries. The second phase inside the grains inhibits the domain wall motion and reduces the mechanical loss, resulting in a considerable increase in mechanical quality factor (Qm) by over 80%. Additionally, the introduction of NiO notably enlarges the grain size by more than 4.5 times. The combination of the second phase and the increased grain size synergistically preserves piezoelectric coefficients (d33). Our study uncovers an innovative method to enhance Qm without significantly compromising d33.