Electrocaloric effect in (1-x) PIN-xPT relaxor ferroelectrics

The electrocaloric effect (ECE) is investigated in both relaxor as well as morphotropic composition of (1 - x) Pb(In1/2Nb1/2) O3-xPbTiO3 system. The ECE is analyzed by evaluating the electrocaloric temperature change (Delta T) using thermodynamic Maxwell equation. The relaxor phase (x = 0.15) show an anomalous broadening in ECE and the maximum of Delta T is found to shift from the proximity of depolarization temperature (T-d) to around T-m' with increase in electric field. However, for morphotropic composition (x = 0.33) a region with negative Delta T is observed below T-d along with anomalous broadening in positive Delta T in the proximity of T-RT. The maximum value of Delta T obtained for relaxor phase is 0.37 K whereas 0.12 K is observed for morphotropic composition at 225C. The electrocaloric responsivity xi(max) is 0.21 mmK/kV for relaxor phase whereas 0.06 mmK/kV is obtained for the morphotropic composition at 18 kV/cm electric field. (C) 2015 Elsevier B.V. All rights reserved.