Origin of enhanced piezoelectric properties revealed through electric field driven studies in 0.94(Na_(0.5)Bi_(0.5)TiO_3)-0.06(Ba_(0.85)Ca_(0.15)Ti_(0.9)Zr_(0.1)O_3) ceramics

摘要

A single phase 0.94(Na_(0.5)Bi_(0.5)TiO_3)-0.06(Ba_(0.85)Ca_(0.15)Ti_(0.9)Zr_(0.1)O_3) solid solution (i.e., BCZT-0.06) is prepared using a conventional solid-state sintering route with enhanced piezo and ferroelectric properties as compared to Na_(0.5)Bi_(0.5)TiO_3 (NBT). In the context of understanding the origin of enhanced piezoelectric properties in a BCZT-0.06 specimen, electric field driven studies on different length scales, viz., global, local, and electronic structure, are carried out using x-rayeutron diffraction, Raman scattering, and UV-Vis spectroscopic techniques. An analysis on different length scales of the electric field-driven BCZT-0.06 specimen displays minimum rhombohedral lattice distortion (δ_r), reduced homogeneous lattice strain (δ), octahedral strain (ζ) and pronounced Ti-cation displacement along the polar [111] direction as compared to parent NBT. The enhanced ferro and piezoelectric responses observed in the BCZT-0.06 specimen have been attributed to the ease of non-180° domain re-orientation, domain switching, and domain wall motion due to reduced strain coupled with a polarization extension mechanism.