A Rhombohedral Structure-Properties Relation in Pb-free Bi-0.5(Na1-xKx)(0.5)TiO3 Ceramics

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

来源：Journal of the Korean Physical Society, 2012, 60(2): 284-287.

DOI：10.3938/jkps.60.284

• Pb-free ceramics
• Lattice distortion
• Depolarization temperature
• Piezoelectric coefficient

A structure-properties relation in Bi-0.5(Na1-xKx)(0.5)TiO3 ceramics was investigated for K contents ranging from 0 to 20 mol% substituting for Na in (Bi0.5Na0.5)TiO3 ceramics. A rhombohedral perovskite solid solution was confirmed up to x = 18 mol%. An inverse relation between depolarization temperature (T-d) and piezoelectric coefficient (d(33)) was observed in the rhombohedral phase region. As x increased toward the morphotropic phase boundary (MPB), T-d was lowered while d(33) was enhanced. Structurally, the rhombohedral lattice distortion (90-alpha) decreased while the lattice constant (alpha(R)) increased with increasing x. 90-alpha appeared to be coupled with the composition-dependent variations in T-d and d(33); the smaller 90-alpha, the lower T-d, and the higher d(33).

• 出版日期2012-1