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 Bi0.5K0.5TiO3-0.01NaNbO(3))-xSrTiO(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 degrees C and 140 degrees 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. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.