Lead-Free Piezoelectric Ceramics of (Bi_1/2Na_1/2)TiO₃–1/2(Bi₂O₃·Sc₂O₃) System

Abstract

Bismuth sodium titanate, (Bi 1/2 Na 1/2 )TiO 3 (BNT)-based solid solution, (1- x )(Bi 1/2 Na 1/2 )TiO 3 – x 1/2(Bi 2 O 3 ·Sc 2 O 3 ) [BNST-100 x ], was studied in order to determine its dielectric, ferroelectric and piezoelectric properties as a new group of lead-free piezoelectric ceramics. Measurements of dielectric and piezoelectric properties show that the BNST-100 x ceramics of composition near BNT composition have relatively low free permittivity, ε 33 T / ε 0 (=431) and high electromechanical coupling factor, k 33 (=0.42). These ceramics are good candidates for use as lead-free piezoelectric ceramics.