Synthesis of Na_(0.5)K_(0.5)NbO_3 Piezoelectrics by a Solution Coating Approach

摘要

The solution coating method is shown to provide more homogeneous mixing of the starting powders and purer (Na_(0.5)K_(0.5)NbO_3 (NKN) powder than the conventional method thereby rendering cold isostatic pressing unnecessary. Sintering NKN with potassium copper niobate (KCN) by uniaxial pressing gave a relative bulk density of 92%, d_33 coefficient of 112 pC/N and a loss factor of 1% after 6 h at 1100℃. In contrast, the conventional method yielded 84% relative bulk density and a 31 % loss factor after 6 h at 1100℃ and the sample was too porous to allow for dielectric and piezoelectric measurements.