3.2. Effects of further Nb2O5 doping on the sintering
behavior and piezoelectric properties of CuO-added BNKT
ceramics
To improve the piezoelectric properties of CuO added
BNKT ceramics, Nb was co-doped with CuO. Fig. 3 shows
SEM photographs of BNKT ceramics sintered with 0.02 mol
CuO and y mol Nb2O5 simultaneously. The sintering was also
carried out 975 8C for 2 h in air. Comparison of microstructures
between specimens with and without Nb2O5 elucidates that the
addition of Nb2O5 results in faceted grain morphology as well
Fig. 1. The surface SEM micrographs of undoped and x mol CuO doped BNKT
ceramics sintered at 975 8C for 2 h in air.
Fig. 3.