Improved aging behavior of lead-free (Na,K)NbO3-LiSbO3 piezoelectric actuators

Abstract

Due to environmental concerns, lead-free or lead-content-reduced materials among the piezoelectric materials have been extensively studied with great attention. (Na0.3K3.3)NbO3 (NKN) piezoelectric material has been a representative material for lead-free piezoelectric ceramics, due to its good piezoelectric properties. Adding LiSbO3 in the form of lithium ion (Li+) and antimony ion (Sb5+) into the A-site and B-site of NKN ceramics solved the evaporation and poling problems. In this paper, after the fabrication of (Na0.5K0.5)NbO3-LiSbO3 (NKN-LS) piezoelectric ceramics, regular electric fields of AC bias were applied to the NKN-LS ceramics. Applying bias led to piezoelectric actuators losing their piezoelectric and dielectric properties. The surface microstructure and piezoelectric properties were compared and analyzed before and after the aging process. Adding LS contents retarded the aging rate of NKN-LS, compared with that of NKN ceramics.