Oxygen vacancy engineering in Mn doped PZT-based ceramics enables superior strain memory and low overshoot

The practical application of ferroelectric shape memory ceramics in high-precision actuation systems faces dual constraints from limited strain memory combined with excessive overshoot. To address this challenge, through poling and aging treatments of MnO 2 -doped Pb 0.94 Sr 0.05 La 0.01 (Zr 0.54 Ti 0.46 )0 .9975 O 3 ceramics, we developed a material system demonstrating enhanced strain memory S m (0.38 %) and superior memory-overshoot ratio R mo (3.64). Mechanism investigations reveal oxygen vacancies' pivotal role in enhancing the ferroelectric shape memory effect. The directional arrangement defect dipoles formed by oxygen vacancies enhance asymmetric domain switching to amplify strain memory. Meanwhile, the local pinning effect of oxygen vacancies selectively limits non-memory strain and reduces overshoot. The optimized performance stems from the synergistic interplay of these complementary mechanisms. The proposed methodology establishes a generalizable framework for developing ferroelectric shape memory ceramics, paving the way for industrial-grade shape memory devices.