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In this work, we report a giant strain (0.42%) in lead-free ceramics of (1– x) (0.79Bi 0.5 Na 0.5 TiO 3 –0.20 Bi 0.5 K 0.5 TiO 3 –0.01NaNbO 3)– x SrTiO 3 with x =0.03. Most importantly, ultra-high temperature stability was simultaneously achieved under this giant strain with the variation less than 10% in the range of 20 °C and 140 °C. Systematic temperature dependent Raman spectra measurements and Ginzburg–Landau–Devonshire thermodynamic theory analysis revealed that the intrinsic lattice strain and electric field induced relaxor-ferroelectric phase transition provide reverse strain response with the increase of temperature, jointly conducive to the ultra-high temperature stability of strain property. These materials are extremely competitive in practical application of actuators. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The grinding strain induced ferroelectric (FE) to antiferroelectric (AFE) phase transition with associated hysteresis loops tuning were found in bulk Pb 0.99 (Zr 0.97 Ti 0.03) 0.98 Nb 0.02 O 3 ceramics. The induced AFE phases can keep stable unless applying heat treatment or electric field. The atomic-scale characterizations reveal that the perfect coherent FE/AFE interface appears either diffuse or sharp depending on its relative orientation to polarization. The induced surface AFE layers on FE bulk can tune hysteresis loops from symmetric to asymmetric and this effect increased with the decrease of thickness of samples. These findings provide new pathway for manipulate phase state and discover novel properties in ferroics. Grinding strain induced ferroelectric-antiferroelectric phase transition with hysteresis loops tuning in bulk ceramics. Image, graphical abstract [ABSTRACT FROM AUTHOR]