Additive effects on electrical properties of (Bi1/2Na1/2)TiO3 ferroelectric ceramics

Microstructure, dielectric, ferroelectric and piezoelectric properties of b ismuth sodium titanate (Bi1/2Na1/2)TiO3 (BNT) were studied for a candidate as lead-free piezoelectric ceramics. In the case of Mn addition, the Curie temperature, T-c, decreases rapidly with increasing amount of doped MnCO3. The resistivity, p, is enhanced to 3 x 10(14) (Omega cm) (at 40 degreesC) f or BNT + MnCO3 0.2 (wt. %) and electromechanical coupling factor, k(33), Wa s obtained the relatively high value under the condition of the low poling field, Ep for the Mn-doped BNT ceramics. It seems that Mn ions exist in the grain, and substitute for the A- or B-site of the perovskite structure, an d eject Bi ions to the air. (C) 2001 Elsevier Science Ltd. All rights reser ved.