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

• W/Ni codped BIT ceramics were sintered at low temperature.
• W dopants decrease the degree of lattice distortion.
• The increasing resistivity is attributed to alleviation of underbonding of Bi ions.
• Oxygen vacancy is responsible for dielectric dispersion and DC electrical conduction.
• The ferroelectricity of BITWN-12 ceramic was systematically studied.

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 °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 °C to 624 °C, whereas both DC resistivity and piezoelectric properties increased. The highest piezoelectric constant (d33 ~ 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).