Large and Stable Shape Memory Effect Realized by Defect Dipoles in Acceptor-Doped Ferroelectric Ceramics

A large and stable shape memory effect has been observed in 0.6wt% Mn-doped (Pb0.99Nb0.02)[(Zr0.70Sn0.30)(0.52)Ti-0.48](0.98)O-3 (Mn:PNZST) ceramics after being poled at high temperature. A maximum shape memory of 0.41% was achieved. This effect is related to the preferentially oriented defect dipoles along the poling direction after poling at high temperature and electric field. Furthermore, the shape memory effect is stable after 10(4) electric cycles at 30kV/cm. The shape memory piezoelectric actuator may be fabricated using this kind of material.