High antiferroelectric stability and large electric field–induced strain in MnO 2 -doped Pb 0.97 La 0.02 (Zr 0.63 Sn 0.26 Ti 0.11 )O 3 ceramics

Crystal structure and electrical properties of MnO₂-doped Pb_0.97La_0.02(Zr_0.63Sn_0.26Ti_0.11)O₃ antiferroelectric ceramic were studied in detail in this article. X-ray diffraction analysis showed that all specimens took on single tetragonal antiferroelectric structure, and antiferroelectric phase stability enhanced with the increase of MnO₂ addition, which was because that the substitution of Mn²⁺ or Mn³⁺ with large ion radius for B-site Ti⁴⁺ decreased the tolerance factor of the ceramic. In addition, it was observed that different from Mn doping reducing Tm of ferroelectric ceramics, Tm of antiferroelectric ceramics increased with the addition of MnO₂, which is for the reason that MnO₂ addition enlarged the zone of antiferroelectric phase. Furthermore, by increasing MnO₂ content, the strain first increased and then decreased. Meanwhile, the value improved obviously as the measuring frequency decreased. The largest electric field–induced strain of 0.65% was obtained in the specimen with 0.2 mol% MnO₂ doping at the frequency of 1 Hz, which lay a foundation for preparing actuator with high strain energy density.