Large Strain Response in the Ternary Bi 0.5 Na 0.5 TiO ₃ – BaTiO ₃ – SrTiO ₃ Solid Solutions

A ternary solid solution (0.935‐ x ) B i 0.5 N a 0.5 T i O 3 –0.065 B a T i O 3 – x S r T i O 3 was designed and fabricated using a conventional fabrication process. Temperature and composition dependence of the ferroelectric, dielectric, and piezoelectric properties were systematically investigated and a schematic phase diagram was established. The S r T i O 3 substitution was found to induce a transition from ferroelectric to relaxor pseudocubic phases. Around a critical composition x of 0.22, large strain response of ~0.2% (under a moderate field of 4 kV/mm) with normalized strain of 490 pm/V was obtained. The large unipolar strain response would be of great interest for environmental‐friendly “on‐off” actuators.