Preparation of (K_(0.50)Na_(0.50))NbO_3 Lead-Free Piezoelectric Ceramics by Mechanical Activation Assisted Method

摘要

A study concerning the synthesis of (Na_(0.50)K_(0.50))NbO_3 was carried out using an economical mechanical activation route from stoichiometric K_2CO_3/ Na_2CO_3/Nb_2O_5 mixture. A pure perovskite phase was obtained by a thermal treatment at 500 °C from the activated mixture, and this temperature is 300-350 °C lower than that required in solid-state reactions. By using the refined powders derived from mechanically activated route, dense (Na_(0.5)K_(0.5))NbO_3 ceramics with enhanced properties were obtained. Its room temperature P_r, d_(33) ,k_p, and dS/dE reached up to 29-37 μC/cm2, 127-135 pC/N, 32-35%, and 222-248 pm/V, respectively, suggesting that the mechanical activation assisted method would be an attractive approach for the industrial fabrication of KNN-based ceramics.