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