Current Applied Physics, Vol.13, No.6, 1055-1059, 2013
Fabrication of textured KNNT ceramics by reactive template grain growth using NN templates
Lead-free non-stoichiometric (K0.470Na0.545)(Nb0.55Ta0.45)O-3 (KNNT) textured ceramics were prepared by a reactive templated grain growth method using NaNbO3 (NN) templates. The Plate-like NaNbO3 (NN) templates were synthesized from bismuth layer-structured Bi2.5Na3.5Nb5O18 (BNN) particles by a topochemical microcrystal conversion (TMC) method. Using 5 wt% of NN templates, textured KNNT ceramics were fabricated, and their crystal structure, microstructure, dielectric and piezoelectric properties were compared with non-textured KNNT ceramics prepared by a conventional solid state reaction method. The textured KNNT ceramics exhibited high grain orientation and high dielectric constant. In addition, piezoelectric properties of textured KNNT ceramics were improved, giving a high piezoelectric coefficient d(33) = 390 pC/N and piezoelectric coupling coefficient k(p) = 0.60. (C) 2013 Elsevier B.V. All rights reserved.