A-site Effects on the Dielectric and the Piezoelectric Properties of (Na0.50+xK0.50-x)(Nb0.55Ta0.45)O-3 Ceramics

作者：Lee J H^*; Ryu G H; Cho J H; Song T K; Kim M H; Park T G; Do D; Kim S S; Sung Y S; Baik S

来源：Journal of the Korean Physical Society, 2012, 60(2): 297-300.

DOI：10.3938/jkps.60.297

• Morphotropic phase boundary
• Polymorphic phase transition
• NKNT

(Na0.5+xK0.5-x)(Nb0.55Ta0.45)O-3 (NKNT) ceramics prepared by using a solid state process were investigated for various A-site ratios between Na and K at 0 %26lt;= x %26lt;= 0.05 to determine the morphotropic phase boundary (MPB). Within the compositional range tested, X-ray diffraction patterns showed NKNT perovskite peaks with no apparent secondary peaks. Scanning electron microscope images showed little difference among microstructures composed of cube-like grains. The piezoelectric coefficient (d(33)) was enhanced up to 310 pC/N at x = 0.03 from 262 pC/N at x = 0 and then decreased with further increases in x while the polymorphic phase transition (PPT) temperature (TO-T) located around room temperature varied little with x. As a result, the increase that occurred in d33 was mainly due to the MPB effects with the MPB composition of the NKNT ceramics at (Na0.53K0.(47)).

• 出版日期2012-1