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

Abstract

A pseudocubic-tetragonal-orthorhombic (PC-T-O) multi-structure was developed in the 0.96(K 0.5 Na 0.47 Li 0.03 ) (Nb 0.92 Sb 0.08 )O 3 -0.04(Ca 0.5 Sr 0.5 )ZrO 3 [(KN 0.47 L 0.03 )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 (KN 0.47 L 0.03 )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 (KN 0.47 L 0.03 )NS-CSZ thick film exhibited excellent fatigue characteristics and was utilized to fabricate a planar-type actuator, which achieved a large displacement (300 μm) and acceleration (872 G) at 125 V/mm. A cantilever-type multilayer actuator was also prepared using five layers of the (KN 0.47 L 0.03 )NS-CSZ thick film and demonstrated a large displacement (3500 μm) and acceleration (42.96 G) at 250 V/mm. Therefore, the (KN 0.47 L 0.03 )NS-CSZ thick film is a good candidate for fabricating various piezoelectric actuators.