Grain-size effect on electrical properties of (Bi1/2K1/2)TiO3 ceramics

In this study, Bi2O3-doped bismuth potassium titanate, (Bi1/2K1/2)TiO3, (abbreviated to BKT-Bix; x = 0, 0.1, 0.2, 0.4, and 0.6 wt %) ceramics were fabricated by hot-pressing method, and its electrical properties were investigated in detail. Moreover, BKT-Bi0.6 was annealed at 1040 degrees C for 4-20 h to develop grains [abbreviated to BKT-Bi0.6(y, h); y = 4, 10, and 20]. The ferroelectric properties were improved by grain growth, and the remanent polarization, P-r, of BKT-Bi0.6(10 h) was 27.6 mu C/cm(2). The piezoelectric properties were improved by field cooling method, and the electromechanical coupling factor, k(33), and piezoelectric constant, d(33), of BKT-Bi0.6(l 0 h) improved up to 0.40 and 101 pC/N, respectively. Moreover, the temperature dependences of piezoelectric properties were measured, and piezoelectricity disappeared at 280 degrees C for BKT-Bi0.6(10h).