Microstructure and Piezoelectric Properties of Lead-Free Niobate Ceramics

Recently perovskite niobates were paid much attention as lead-free piezoelectric materials to replace lead-based Pb(Zr,Ti)O3 or relaxor systems which cause much environmental problems. Piezoelectric and ferroelectric properties of electromechanical coupling coefficient and quality factor in (K0.5Na0.5)NbO3 ceramic were studied. Dielectric properties of niobates including Ag ion; AgNbO3 and (Ag0.5Na0.5)NbO3 were studied. Phase transitions and dielectric relaxations were studied from the frequency and temperature dependent dielectric constant measurements. The piezoelectric properties were hardly observed in silver niobate systems.