Fabrication and Physical Properties of Na(Nb1-xSbx)O3 Templates for the [001]-Texturing of KNN-Based Ceramics

Na(Nb1-xSbx)O3 [N(N1-xSx)] templates were fabricated to texture the 0.96(Na0.5K0.5)(Nb1-ySby)O3-0.01BaZrO3-0.03(Bi0.5Ag0.5)ZrO3 [KN(N1-ySy)-BZ-BAZ] piezoceramics along the [001] direction. To the best of our knowledge, this is the first study that fabricated these templates. Thus far, NaNbO3 (NN) templates have been utilized to texture KNN-modified piezoceramics; however, they produce many holes in the piezoceramics because of the dissolution of the NN templates during sintering. N(N0.9S0.1) templates with an average size of ~18 μm were produced by the molten-salt and topochemical methods utilizing Bi2.5Na3.5(Nb0.9Sb0.1)5O18 precursors. Due to their high melting temperature, the N(N0.9S0.1) templates did not dissolve during sintering. Therefore, no holes were present in the KN(N0.95S0.05)-BZ-BAZ piezoceramic textured using the N(N0.9S0.1) templates. The piezoceramic textured using the N(N0.9S0.1) templates showed a large hardness (7.56 ± 0.26GPa) and an elastic modulus (154 ± 5GPa) similar to those of the untextured piezoceramic. However, the piezoceramic textured using the NN templates showed reduced hardness (5.94 ± 0.58GPa) and elastic modulus (127 ± 14GPa) because of the presence of the holes. The KN(N0.95S0.05)-BZ-BAZ piezoceramics textured using the N(N0.9S0.1) templates provided large d33 (740 pC/N) and kp (0.62) values. Cantilever-type piezoelectric energy harvesters (CPEHs) were produced using the KN(N0.95S0.05)-BZ-BAZ piezoceramic textured with N(N1-xSx) templates and the CPEH produced using the piezoceramic textured by N(N0.9S0.1) templates generated the largest power of 2.92mW. Therefore, N(N0.9S0.1) is a promising template for the [001] texturing of KNN-based piezoceramics with good mechanical properties.