Suppressed tanδ and enhanced Qm in KCT and Ni2O3 co-modified [(K0.43Na0.57)0.94Li0.06] [(Nb0.94Sb0.06)0.95Ta0.05O3 lead-free piezoelectric ceramics

Effects of K5.4Cu1.3Ta10O29 (KCT) doping on structural and electrical properties of 0.05 mol% Ni2O3 modified [(K0.43Na0.57)(0.94)Li-0.06][(Nb0.94Sb0.06)(0.95)Ta-0.95]O-3 (KNLNST) ceramics have been studied. It is found that the addition of suitable amount KCT can significantly enhance Q(m) and suppress land while virtually maintaining d(33) of the ceramics. The 0.2 mol% KCT added KNLNST +0.05 mol% Ni2O3 ceramic shows a high Q(m) (similar to 180) and a very low tan delta (0.82%), which are respectively nearly four times and a quarter of those of pure KNLNST +0.05 mol% Ni2O3 ceramic. Meanwhile, d(33) and k(p) of this ceramic maintain relatively high values (d(33)=287 pC/N, k(p)=46.2%). The dramatic change of Q(m) (tan delta) and virtual maintenance of d(33) (k(p)) are mainly attributed to the effects of Cu2+ and K+ in KCT, respectively. High Q(m) and d(33) but remarkably low tan delta indicates large potential of this ceramic for making high power transducer devices.