Grain oriented CaBi4Ti4O15 piezoceramics prepared by the screen-printing multilayer grain growth technique

The grain oriented bismuth layer structure ferroelectric (BLSF) ceramics have superior ferroelectric and piezoelectric properties to the randomly oriented ceramics. The grain oriented CaBi4Ti4O15 ceramics were prepared by the screen-printing multilayer technique without any template particles. The influences of sintering time, temperature, and the particle size of raw materials on grain orientation were studied. The degree of grain orientation and the grain morphologies were examined using XRD and SEM techniques. At sintering temperatures of 1000–1120 °C, orientation degree increases with sintering temperature and keep constant at temperatures of 1120–1150 °C. The orientation degree increases rapidly with sintering time at beginning and gradually reaches the highest value for 4 h at the sintering temperature. It was found that the particle size of starting materials is the important factor for grain orientation. Highly oriented ceramics can be obtained only when using nanosized starting materials. Without the use of template particles and pressure densification process, the screen-printing multilayer grain growth (MLGG) technique is a new approach to fabricate highly textured piezoceramics.