Electrocaloric effect in lead-free relaxor (1-x)(Sr0.7Bi0.2)TiO3+x(Na0.5Bi0.5)TiO3 material system

The relationship between electrocaloric effect (ECE) and electrostrictive strain over a broad electric field was studied in (1-x)(Sr0.7Bi0.2)TiO3+x(Na0.5Bi0.5)TiO3 relaxor based lead-free ceramics, where the electric field induced strain can reach the level of 0.28% at 12 MV/m. The experimental data revealed that the composition with highest strain response also generated the largest ECE near room temperature, e.g., ΔS=3.6 J kg−1 K−1 and an adiabatic temperature change ΔT=2.4 K at 13 MV/m. This research provides an effective approach for designing new ECE materials.