Enhanced Piezoelectric Properties of Li⁺ and Al³⁺-Modified Barium Titanate Ceramics

Ba(1-2x)LixAlxTiO₃ (x=0, 0.5, 1.5 and 2.5 mol%) ceramics were prepared by a conventional sintering method. The effects of Li⁺ and Al³⁺ content on the crystalline structure, dielectric and piezoelectric properties of BT ceramic were investigated. A better incorporation of Li⁺ and Al³⁺ ions recently occurs in our system without any impurity at x≤1.5 mol%. Ba(1-2x)LixAlxTiO₃ ceramic can generate a large piezoelectric constant of d33=276 pC/N at x=1.5 mol%. According to the dielectric properties results, the high piezoelectricity is possible from the suppressed energy barrier of second-like order transition induced by the incorporation of Li⁺ and Al³⁺ ions.