Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1611612 | Journal of Alloys and Compounds | 2014 | 5 Pages |
•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).