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Composition dependence of electrocaloric effect is investigated in(1- x)Pb(Mg1/3Nb2/3)O3- xP b Ti O3 single crystals by using an eighth-order Landau–Devonshire theory. The applied electric field along [001] direction reduces the ferroelectric-ferroelectric phase transition temperatures, but increases the Curie temperatures. The electrocaloric coefficients of tetragonal phase are much larger than that of rhombohedral and monoclinic phase. A negative electrocaloric effect is observed near the MC-T phase transition in 0.69Pb(Mg1/3Nb2/3)O3-0.31 Pb Ti O3 single crystal. The application of a strong enough electric field results in a high adiabatic temperature change over a broad range of temperature.Therefore, it would be useful to construct a solid state cooling cycle over a broad temperature range for practical applications.
Composition dependence of electrocaloric effect is investigated in (1- x) Pb (Mg 1/3 Nb 2/3) O 3-xP b Ti O 3 single crystals by using an eighth-order Landau-Devonshire theory. The applied electric field along [001] direction reduces The ferroelectric-ferroelectric phase transition temperatures, but increases the Curie temperatures. The electrocaloric coefficients of tetragonal phases are much larger than that of rhombohedral and monoclinic phases. A negative electrocaloric effect is observed near the MC-T phase transition in 0.69Pb (Mg1 / 3Nb2 / 3) O3-0.31 Pb Ti O3 single crystal. The application of a strong enough electric field results in a high adiabatic temperature change over a broad range of temperature. Herefore it would be useful to construct a solid state cooling cycle over a broad temperature range for practical applications