Excellent temperature stability with giant electrostrain in Bi0.5Na0.5TiO3-based ceramics.

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]