The effect of composite (Li_(0.5)Nd_(0.5))~(2+) ions substitution on microstructure, dielectric behavior and electrical properties of 0.95Bi_(0.5)Na_(0.5)TiO_3-0.05BaTiO_3 ceramics

摘要

New lead-free 0.95(Bi_(0.5)Na_(0.5))_(1-x)(Li_(0.5)Nd_(0.5)TiO_3-0.05BaTiO_3(BNTLN_x-BT5) ceramics with x=0, 0.01, 0.03, 0.05, 0.07, 0.1 have been fabricated by conventional solid-state method. The effect of composite (Li_(0.5)Nd_(0.5))~(2+) ions substitution on microstructure, dielectric behavior and electrical properties was investigated. A morphotropic phase boundary (MPB) separating the rhombohedral phases and pseudocubic phases is observed at the compositions x=0.01-0.03. The grain size increases at compositions x=0-0.07 and decreases at composition x=0.1. At room temperature, the frequency dispersion of dielectric constant ε_r strengthens with increasing x. The temperature stability coefficient f_ε of dielectric constant ε at T= 23-230 °C decreases from 28.35 to 6.18 with increasing x. The ceramics exhibit a largest dispersion coefficient (γ= 1.90) and a largest piezoelectric constant (d_(33)=135pC/N) at x=0.07.