Effect of Ta-Substitution on the Ferroelectric and Piezoelectric Properties of Bi_0.5/(Na_0.82K_0.18)_0.5TiO₃Ceramics

Abstract

The effect of Ta substitution on the crystal structure, ferroelectric, and piezoelectric properties of Bi 0.5 (Na 0.82 K 0.18 ) 0.5 Ti 1-x Ta x O 3 ceramics has been investigated. The Ta doping resulted in a transition from coexistence of ferroelectric tetragonal and rhombohedral phases to an electrostrictive pseudocubic phase, leading to degradations of the remnant polarization, coercive field, and piezoelectric coefficient d 33 . However, the electricfield-induced strain was significantly enhanced by the Ta substitution-induced phase transition and reached a highest value of S max /E max = 566 pm/V under an applied electric field 6 kV/mm when 2% Ta was substituted on Ti sites. The abnormal enhancement in strain was attributed to the pseudocubic phase with high electrostrictive constants.

The effect of BZT doping on phase formation, dielectric and ferroelectric properties of BNLT ceramics

“…It can be seen from the results that both of the BZT substitution and the increase in temperature caused the development of the P-E relaxor loops [60,61]. The similar behavior can be also seen in many other BNT-based materials [62][63][64][65].…”

Strain enhancement in Bi1/2(Na0.82K0.18)1/2TiO3 lead-free electromechanical ceramics by co-doping with Li and Ta

“…More recently, it was found that large strains in BNKT (Na/K = 82/18 or 78/22) ceramics can be observed when B-site Ti ions are substituted with either isovalent ions such as Hf [18] and Zr [19] or aliovalent ions including Nb [20] and Ta [21]. In light of this observation, it is useful to examine the effect of simultaneous A-and B-site substitution on EFIS in BNKT.…”

Tailoring ergodicity through selective A-site doping in the Bi1/2Na1/2TiO3–Bi1/2K1/2TiO3 system

“…6,7 Several reports have focused on modifying the system through solid solutions achieving promising large signal strain properties, namely, d 33 * above 500 pm/V at 6 kV/mm. [8][9][10][11][12] Other studies focused on either A-and/or B-site doping to improve small and large signal electromechanical properties. [13][14][15][16] It was proved that either replacing Bi on the A-site 16 or all A-site cations are effective approaches.…”