Preparation and dielectric property of (Li_0.12Na _0.88)NbO₃-based solid solutions

Three solid solutions [(1-x)LNN-xBaTiO₃ (BT), xBaZrO₃ (BZ) and xK_0.5Ba_0.5Ti_0.5Nb_0.5O ₃(KBTN)] based on (Li_0.12Na_0.88)NbO ₃(LNN) with the rhombohedral symmetry were prepared by conventional solid state reaction and their dielectric property was investigated. In the LNN-BT system in x ≤ 0.6 a secondary phase was observed as well as the perovskite-type phase and the psudo-cubic and tetragonal single phases were observed in 0.7 ≤ x ≤ 0.94 and 0.95≤ x ̄ 1.0, respectively. In LNN-BZ and LNN-KBTN systems single phases of the compounds with the rhombohedral symmetry were formed in x ≤ 0.05. The length of the a-axis increased with content of BZ or KBTN and that of the c-axis was almost unchanged except x = 0.1 for LNN-BZ. The secondary phase with the tetragonal tungsten bronze-type (TTB) structure was observed in wide composition range of these solid solutions, and Li_xBa₂NaNb_5-xM_xO₁₅(M: Ti, Zr) with the TTB-type structure was prepared and their crystal structure and dielectric property were investigated.