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

Abstract Effects of K 5.4 Cu 1.3 Ta 10 O 29 (KCT) doping on structural and electrical properties of 0.05 mol% Ni 2 O 3 modified [(K 0.43 Na 0.57 ) 0.94 Li 0.06 ][(Nb 0.94 Sb 0.06 ) 0.95 Ta 0.05 ]O 3 (KNLNST) ceramics have been studied. It is found that the addition of suitable amount KCT can significantly enhance Q m and suppress tan δ while virtually maintaining d 33 of the ceramics. The 0.2 mol% KCT added KNLNST +0.05 mol% Ni 2 O 3 ceramic shows a high Q m (~180) and a very low tan δ (0.82%), which are respectively nearly four times and a quarter of those of pure KNLNST +0.05 mol% Ni 2 O 3 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 δ ) and virtual maintenance of d 33 ( k p ) are mainly attributed to the effects of Cu 2+ and K + in KCT, respectively. High Q m and d 33 but remarkably low tan δ indicates large potential of this ceramic for making high power transducer devices.