Composition dependence of phase boundary and electrical properties in lead-free (K 0.5 Na 0.5 )(Nb 0.96 Sb 0.04 )O 3 –Bi 0.5 Na 0.5 ZrO 3 –Bi 0.5 Li 0.5 ZrO 3 ceramics

In this work, (K 0.5 Na 0.5 )(Nb 0.96 Sb 0.04 )O 3 –Bi 0.5 Na 0.5 ZrO 3 –Bi 0.5 Li 0.5 ZrO 3 lead-free ceramics were fabricated by the conventional solid-state method, and effects of Bi 0.5 Li 0.5 ZrO 3 on their phase structure and electrical properties were studied. Their piezoelectric properties are sensitive to the addition of Bi 0.5 Li 0.5 ZrO 3 as well as its contents. The addition of Bi 0.5 Li 0.5 ZrO 3 simultaneously increased their Curie temperature and decreased rhombohedral and tetragonal phase transition temperature. Their dielectric, ferroelectric, and piezoelectric properties were strongly dependent on Bi 0.5 Li 0.5 ZrO 3 contents. With increasing Bi 0.5 Li 0.5 ZrO 3 contents, their dielectric loss can be decreased, and their k p and P r values can be further optimized. However, their ε r and d 33 slightly decreased with the increase of Bi 0.5 Li 0.5 ZrO 3 contents due to the deviation of rhombohedral and tetragonal phase boundary, and the ceramics with x ≤ 0.2 exhibited a high d 33 of >410 pC/N. As a result, this work could further understand the role of Bi 0.5 Li 0.5 ZrO 3 in electrical properties of high-performance alkali niobate ceramics.