Effects of thermal and electrical histories on structure and dielectric behaviors of (Li0.5Nd0.5)2+-modified (Bi0.5Na0.5)TiO3-BaTiO3 ceramics

摘要

The effect of thermal and electrical histories on structure and dielectric behaviors is studied using 0.95(Bi_0.5Na_0.5)_0.97(Li_0.5Nd_0.5)_0.03TiO₃-0.05BaTiO₃ (abbreviated as BNTLN0.03-BT5) ceramic as a selected system. Subtle structure change caused by annealing treatment, and pronounced phase transition and domain switching by electrical poling, are observed to occur, respectively. The dielectric constant and its strong frequency dispersion in unpoled samples decrease evidently by electrical poling due to electric field-induced ordered domain. The high temperature Maxwell-Wagner relaxor behavior vanishes by annealing treatment due to the loss of electrical inhomogeneity with interface charging effects. Piezoelectric properties are improved evidently by annealing treatment at 900?°C, implying a new appropriate method to improve piezoelectric properties.