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 (d(33)) and wide sintering temperature range (T-s) in the 0.955(K0.42Na0.58)(Nb0.96Sb0.04)O-3-0.045-(Bi0.5K0.5)(0.90)Zn0.10ZrO3 lead-free ceramics. Dense microstructures were developed in the ceramics by two-step sintering. In the T-s range of 800-1130 degrees 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 d(33) of 323-416 pC/N could be attained in a temperature gap range of 330 degrees C. We believe that the two-step sintering could both widen the sintering temperature and obtain a high d(33) for this material system.