Phase structure and piezoelectric properties of Ca-and Ba-doped K1/2Na1/2NbO3 lead-free ceramics

JONATHAN TAUB; LEANDRO ALDREDO RAMAJO; MIRIAM SUSANA CASTRO

CERAMICS INTERNATIONAL

ELSEVIER SCI LTD

Año: 2012 vol. 39 p. 3555 - 3561

0272-8842

Piezoelectric lead-free ceramics, K1/2Na1/2NbO3 (KNN) modified with alkaline-earth (AE) Ca2+ and Ba2+, have been prepared by the conventional solid-state reaction method. The effect of doping level on sinterability and functional response of KNN was studied. In this way, discs doped with 0 to 2 mol% of Ba2+ and Ca2+ were sintered at 1125 ºC for 2h. It was observed that AE changed drastically the microstructure and grain size of KNN when it was added in concentrations higher than 0.5 mol%. Addition of 0.5mol% of Ba2+ and Ca2+ produced a softening effect in the ferroelectric properties of the material, while samples prepared with higher contents than 0.5mol% showed poor properties.