(Bi _1/2 Na _1/2 )TiO ₃ –Ba(Cu _1/2 W _1/2 )O ₃ Lead‐Free Piezoelectric Ceramics

Abstract

(Bi 1/2 Na 1/2 )TiO 3 with 0–6 mol% Ba(Cu 1/2 W 1/2 )O 3 (BNT‐BCW), a new member of the BNT‐based group, has been prepared following the conventional mixed oxide route. The compacted bodies were sintered at 1130°C for 2 h to get dense ceramics. The addition of BCW into BNT ceramics facilitated the poling process because of a reduction in leakage current. 0.995BNT·0.005BCW ceramics exhibit a relatively high piezoelectric constant ( d 33 = 80 × 10 −12 C/N) and a relatively low dielectric loss (tan δ= 1.5%). Increased amount of BCW was found to increase the dielectric constant and loss of BNT‐BCW ceramics and to suppress the grain growth. During sintering, some BCW diffuses into the lattice of BNT to form a solid solution and some remains on the grain boundaries.