SmAlO3-modified (K0.5Na0.5)0.95Li0.05Sb0.05Nb0.95O3 lead-free ceramics with a wide sintering temperature range

Lead-free ceramics (1 - x)(K0.5Na0.5)(0.95)Li0.05Sb0.05Nb0.95O3-xSmAlO(3) (KNLNS-xSA) were prepared by conventional sintering technique. The phase structure, dielectric and piezoelectric properties of the ceramics were investigated. All compositions show a main perovskite structure, exhibiting room-temperature symmetries of tetragonal at x <= 0.0075, of pseudo-cubic at x = 0.0100. The Curie temperature of KNLNS-xSA ceramics decreases with increasing SmAlO3 content. Moreover, the addition of SmAlO3 can effectively broaden the sintering temperature range of the ceramics. The KNLNS-xSA ceramic with x = 0.0050 has an excellent electrical behavior of piezoelectric coefficient d(33) = 226 pC/N, planar mode electromechanical coupling coefficient k(p) = 38%, dielectric loss tan delta = 3.0%, mechanical quality factor Q(m) = 60, and Curie temperature T-c = 327 degrees C, suggesting that this material could be a promising lead-free piezoelectric candidate for piezoelectric applications. (c) 2013 Elsevier B.V. All rights reserved.