Advanced Physical Research

This study used a molten salt method to fabricate the templates of Bi₄Ti₃O₁₂ (BIT). The as-synthesized BIT templates exhibited orthorhombic perovskite structures with 5–20 µm long and 0.5–1 µm wide plate-like morphologies. The results showed that using BIT templates improved the piezoelectric properties of the (1 – x)(K_0.48Na_0.48Li_0.04)(Nb_0.95Sb_0.05)O₃ – xBi₄Ti₃O₁₂ ceramics [(1 – x)KNLNS – xBIT ceramics, x = 0.0, 0.01, 0.02, and 0.03)]. The experimental results revealed that the (1 – x)KNLNS – xBIT samples sintered at 1100⁰C had pure perovskite phases for a low BIT content (x ≤ 0.02). The (1 – x)KNLNS – xBIT sample sintered at 1100⁰C showed good densification behaviors and a high density for a 0.02 mol BIT content. The 0.98KNLNS – 0.02BIT ceramics exhibited a high ceramic density of 4.51 g/cm³, with a fairly uniform microstructure, clear grain boundaries, and a 1.29 µm large grain size. Optimum piezoelectric properties of k_p = 0.36, d₃₃ = 189 pC/N, ε_r = 1017, Q_m = 115, and a high Curie temperature T_C = 381⁰C were obtained in 0.98 KNLNS–0.02BIT ceramics.