title: Large electrocaloric effect in ferroelectric polymers near room temperature.
abstract: Applying an electrical field to a polar polymer may induce a large change in the dipolar ordering, and if the associated entropy changes are large, they can be explored in cooling applications. With the use of the Maxwell relation between the pyroelectric coefficient and the electrocaloric effect (ECE), it was determined that a large ECE can be realized in the ferroelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] copolymer at temperatures above the ferroelectric-paraelectric transition (above 70 degrees C), where an isothermal entropy change of more than 55 joules per kilogram per kelvin degree and adiabatic temperature change of more than 12 degrees C were observed. We further showed that a similar level of ECE near room temperature can be achieved by working with the relaxor ferroelectric polymer of P(VDF-TrFE-chlorofluoroethylene).
authors.affiliation: Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Bret
authors.initials: B
authors.lastname: Neese
authors.forename: Baojin
authors.initials: B
authors.lastname: Chu
authors.forename: Sheng-Guo
authors.initials: SG
authors.lastname: Lu
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: E
authors.initials: E
authors.lastname: Furman
authors.forename: Q M
authors.initials: QM
authors.lastname: Zhang