Simultaneous realization of high d33 and large strain in (K,Na,Li) (Nb,Sb) O3-(Ca,Sr)ZrO3 materials and their application in piezoelectric actuators

A pseudocubic-tetragonal-orthorhombic (PC-T-O) multi-structure was developed in the 0.96(K0.5Na0.47Li0.03) (Nb0.92Sb0.08)O-3-0.04(Ca0.5Sr0.5)ZrO3 [(KN0.47L0.03/NS-CSZ] lead-free piezoceramic. The PC structure observed in this sample was deemed to have an R3m rhombohedral structure. This sample demonstrated a large d(33)(560 pC/N) owing to the existence of the PC-T-O multi-structure. The (KN0.47L0.03)NS-CSZ thick film also exhibited a large d(33) (560 pC/N) and strain (0.19% at 4.0 kV/mm). The large strain was sustained even after the application of 10(6) electric-field cycles. Therefore, the (KN0.47L0.03)NS-CSZ thick film exhibited excellent fatigue characteristics and was utilized to fabricate a planar-type actuator, which achieved a large displacement (300 mu m) and acceleration (872 G) at 125 V/mm. A cantilever-type multilayer actuator was also prepared using five layers of the (KN0.47T0.03)NS-CSZ thick film and demonstrated a large displacement (3500 mu m) and acceleration (42.96 G) at 250 V/mm. Therefore, the (KN0.47L0.03)NS-CSZ thick film is a good candidate for fabricating various piezoelectric actuators.