Structural, dielectric, conductive and piezoelectric properties of a new three-layer Bi4−x∕2Nax∕2Ti3−xNb _<i>x</i> O12 Aurivillius phase piezoceramics

A new three-layer Aurivillius phase piezoceramic, Bi[Formula: see text]Na[Formula: see text]Ti[Formula: see text]Nb x O[Formula: see text] ([Formula: see text], 0.03, 0.05 and 0.10), was prepared by the traditional solid-state sintering method. All samples display a uniphase orthorhombic structure and plate-shaped grains. The introduction of Na/Nb inhibits the generation of oxygen vacancies, enhances dielectric stability and resistivity and reduces dielectric loss. Increasing the Na/Nb amount could increase the activation energy [Formula: see text] and enhance the dc resistivity. The dc resistivity of Bi[Formula: see text]Na[Formula: see text]Ti[Formula: see text]Nb x O[Formula: see text] ([Formula: see text]) ceramics has increased to above [Formula: see text] [Formula: see text]cm at [Formula: see text]C and [Formula: see text] [Formula: see text]cm at [Formula: see text]C. The conduction mechanisms of the Bi[Formula: see text]Na[Formula: see text]Ti[Formula: see text]Nb x O[Formula: see text] ceramics are also sufficiently explored. The conducting carriers are mainly oxygen vacancies, and their migration exhibits temperature-dependent relaxation characteristics. The Bi[Formula: see text]Na[Formula: see text]Ti[Formula: see text]Nb[Formula: see text]O[Formula: see text] ceramics obtain the excellent properties of high [Formula: see text]C, small [Formula: see text]C, low [Formula: see text], large [Formula: see text]cm and better [Formula: see text] [Formula: see text]pC/N. This work presents a valid tactic to design Aurivillius phase piezoceramics with enhanced resistivity and piezoelectricity for the field of high-temperature piezoelectricity.