Abstract
Piezoelectric properties of lead-free bismuth layer structure oxide, SrBi4Ti4O15 (SBT) based ceramics, were studied. By means of La substitution and Mn addition, the maximum value of Q (Qmax ) between resonant frequency and anti-resonant frequency was larger than that of SBT. These materials could be utilized in practical applications as substitutes for lead titanate based ceramics (PT) and lead zirconate titanate based ceramics (PZT) which are used mainly in resonators. The reason for the higher Qmax value was identified by microstructual analysis as being due to the absence of a defect structure.