Two-step sintering of new potassium sodium niobate ceramics: a high d33 and wide sintering temperature range

In this work, the two-step sintering technique is used to realize a high piezoelectric constant (d33) and wide sintering temperature range (TS) in the 0.955(K0.42Na0.58)(Nb0.96Sb0.04)O3–0.045(Bi0.5K0.5)0.90Zn0.10ZrO3 lead-free ceramics. Dense microstructures were developed in the ceramics by two-step sintering. In the TS range of 800–1130 °C, the rhombohedral–tetragonal phase boundary was well maintained, and these ceramics possess enhanced dielectric, ferroelectric, and piezoelectric properties. It is of great interest to note that a d33 of 323–416 pC/N could be attained in a temperature gap range of 330 °C. We believe that the two-step sintering could both widen the sintering temperature and obtain a high d33 for this material system.