Correlation between lattice distortion and electrical properties on Bi4Ti3O12 ceramics with W/Ni modifications

Aurivillius phase Bi4Ti3-xWxO12 + 0.2 wt% NiO (BITNW-100x) ceramics were prepared by a conventional sintering method. BINTW-based ceramics were sintered in a low temperature range of 950-1040 degrees C. The crystallographic evolution was determined by the X-ray diffraction, by which the lattice parameters, a and b were calculated. It was found that the increase of the W doping level reduced the lattice distortion of BITNW-based ceramics, which alleviated the degree of ` underbonding' of Bi ions in (Bi2O2)(2+) layers. As a result, the value of Curie temperature decreased from 653 degrees C to 624 degrees C, whereas both DC resistivity and piezoelectric properties increased. The highest piezoelectric constant (d33 similar to 18.5pC/N) was achieved for BINTW-12 ceramics. The detailed studies on ferroelectric property of BITNW-12 ceramic were determined at various temperatures and electric fields. Not only external electric fields but also measurement temperature strongly influenced the value of remnant polarization (Pr). (C) 2013 Elsevier B.V. All rights reserved.