Field-induced thermal response and irreversible phase transition enthalpy change in Pb(Mg1/3Nb2/3)O3–PbTiO3

Abstract

In order to determine the enthalpy change in an irreversible field-induced phase transition, the thermal response to an electric field in 0.87Pb(Mg1/3Nb2/3)O3−0.13PbTiO3 was measured and dismantled into characteristic dielectric hysteresis, reversible electrocaloric, and irreversible phase transition responses. Below the depolarization temperature Tdp=18 °C, the phase transition enthalpy change increases rapidly to a maximum value of |ΔH|=77 J/kg. Above Tdp, the field-induced thermal response shows a reversible nature with an increased electrocaloric effect. In addition to earlier enthalpy data presented for temperature-induced transitions, this letter provides information on the enthalpy change in a field-induced phase transition of relaxor ferroelectrics.