Enhanced electromechanical properties and conduction behaviors of Aurivillius Bi4Ti2.95(B1/3Nb2/3)0.05O12 (B=Mg, Zn, Cu) ceramics

• Electrical properties and conduction behaviors of BTNM, BTNC and BTNZ were studied.
• Electrical properties of them were related to structural distortion and oxygen vacancies.
• BTNM obtained enhanced electromechanical properties (S33=0.061%, d33*=40.7 pC/N).
• BTNM (TC=686 °C) could be promising high-temperature lead-free piezoelectrics.

(B1/3/Nb2/3) (B=Mg, Zn, Cu) co-substituting for Ti4+ in B-site of Bi4Ti3O12-based Aurivillius ceramics were prepared to improve the piezoelectric properties. The electrical properties and conduction mechanisms of them were investigated. The activation energy related with the electrical relaxation determined from the electric modulus spectra was 0.71 eV and the electrical conductivity decreased dramatically by (Mg1/3/Nb2/3)-doping, due to the enhanced structural distortion and the decrease in oxygen vacancy concentration. The (Mg1/3/Nb2/3)-substituted specimen with a Curie point of 686 °C and a large field-induced strain of 0.061% as well as a higher remnant polarization of 12.9 μC/cm2 could be a promising material for high-temperature lead-free piezoelectric applications.