Giant electrostrain under low driving field in Bi1/2Na1/2TiO3-SrTiO3 ceramics for actuator applications

• Published in: Ceramics international Vol. 42; no. 14; pp. 16153 - 16159
• Main Authors: Tong, Xing-Ye, Li, Hai-Long, Zhou, Jia-Jun, Liu, Hong, Fang, Jing-Zhong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2016
• Subjects: Lead-free piezoceramics; Na0.5Bi0.5TiO3; Perovskite; Na0.5Bi0.5TiO3; Lead-free piezoceramics; Perovskite
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2016.07.133

BiMg1/2Ti1/2O3 (BMT)/NaNbO3 (NN) was introduced into the Bi1/2Na1/2TiO3-SrTiO3 lead-free system to modify its phase structure and electrical properties. The ceramics were prepared by a traditional ceramic processing method. All samples exhibited pure perovskite structure, as well as dense microstructures. The modified compositions underwent a phase transition from a ferroelectric phase to an ergodic relaxor state with increasing BMT/NN content. This transition was identified from the decrease in the ferroelectric-relaxor transition temperature to room temperature. When the composition was located in the vicinity of the critical region, giant electrostrain was obtained owing to the field-induced reversible transition between the relaxor and ferroelectric phases. A schematic phase diagram was constructed based on the measured properties. Excellent actuating performance of Smax/Emax>850pm/V with an ultra-low driving field of E≤3kV/mm was achieved in the modified compositions. This performance is comparable to that of the Pb(Zr,Ti)O3-based counterparts and demonstrates the great potential of the current materials in piezoactuator applications.