Enhanced piezoelectricity of [001]-textured (K,Na)(Nb,Sb)O3-(Bi,Ag)ZrO3 ceramics using Na(Nb0.9Sb0.1)O3 templates at low temperature

In this study, 2.0 mol% CuO-added 0.96(K0.5Na0.5)(Nb1-zSbz)O-3-0.04(Bi0.5Ag0.5)ZrO3 [CKN(N1-zSz)-BAZ] piezoceramics (0.0 <= z <= 0.08) were densified at 980 degrees C without the secondary phase. The crystal structure of the CKN(N1-zSz)-BAZ piezoceramics changed from the tetragonal-orthorhombic structure to the tetragonal-orthorhombic-pseudocubic structure with increasing z. The CKN(N1-zSz)-BAZ piezoceramics (0.0 <= z <= 0.07) were well textured at 980 degrees C along the [001] direction, without holes, when 3.0 mol% Na(Nb0.9Sb0.1)O-3 (NNS) templates were used. However, the specimens textured using NaNbO3 (NN) templates exhibited holes owing to the dissolution of the NN templates. Moreover, the elastic modulus and hardness of the specimen (z = 0.05) textured using the NNS template were larger than those of the specimen (z = 0.05) textured using the NN template, possibly because of the absence of holes. The [001]-textured CKN(N1-zSz)-BAZ piezoceramics exhibited a reduced dielectric constant and enhanced piezoelectric properties. Particularly, the [001]-textured CKN(N0.95S0.05)-BAZ piezoceramic provides large d(33) (610 pC N-1), k(p) (0.68) and d(33) x g(33) (30 x 10(-12) m(2) N-1) values. A cantilever-shaped piezoelectric energy harvester was fabricated using the [001]-textured CKN(N0.95S0.05)-BAZ ceramic, which showed a large output power of 1.6 mW at the resonance frequency, indicating that this piezoceramic is a good candidate for a piezoelectric energy harvester.