Effect of Small Amount CuO Doping on Microstructure and Properties of the Alkaline Niobate-Based Lead-Free Ceramics

Recently, it was reported that the alkaline niobate-based (K,Na,Li)(Nb,Ta,Sb)O3 (LF4) perovskite ceramics showed excellent piezoelectric properties and has been regarded as a new candidate of lead-free piezoelectric materials. However, the effects of additives on the piezoelectric property of LF4 have not been studied intensively so far. In this study, the effect of CuO addition to the LF4 was investigated. The sample showed a tetragonal phase at room temperature and also a second phase with low melt point. The Cu2 + can replace both A-site and B-site because of its radii. The mechanical quality factor (Q m ) increased from 26 to 137 as the CuO increased.