Large electrostrain in low‐temperature sintered NBT‐BT‐0.025FN incipient piezoceramics

It is well‐known that the high sintering temperatures of (Na 1/2 Bi 1/2 )TiO 3 (NBT)‐based incipient piezoceramics limit their applications on low‐cost multilayer piezoelectric actuators with base metal internal electrodes. In this work, a synergistic sintering additive of 0.75 wt% Li 2 CO 3 and 0.75 wt% CuO was utilized to explore the effect on sintering behavior and electrostrain of (Na 1/2 Bi 1/2 ) 0.935 Ba 0.065 Ti 0.975 (Fe 1/2 Nb 1/2 ) 0.025 O 3 (NBT‐BT‐0.025FN) incipient piezoceramic. The optimal sintering temperature of NBT‐BT‐0.025FN decreased from 1160°C to 940°C due to the formation of a liquid phase, with limited degradation on electrostrain. When sintered at 940°C, a large strain of 0.39% (a nominal piezocoefficient of 571 pm/V) was achieved, which is promising for potential actuator applications co‐firing with Ag electrodes.