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

Abstract

In this work, the two-step sintering technique is used to realize a high piezoelectric constant (d₃₃) and wide sintering temperature range (T_S) in the 0.955(K_0.42Na_0.58)(Nb_0.96Sb_0.04)O₃–0.045(Bi_0.5K_0.5)_0.90Zn_0.10ZrO₃ lead-free ceramics. Dense microstructures were developed in the ceramics by two-step sintering. In the T_S 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.