Anomalous negative electrocaloric effect in a relaxor/normal ferroelectric polymer blend with controlled nano- and meso-dipolar couplings
Abstract
In general, a dielectric material will eject (or absorb) heat when an electric field is applied and absorb (or eject) heat when the field is removed, under isothermal condition, which is known as the normal (or negative) electrocaloric (EC) effect. For some applications, it is highly desired that an EC material will absorb heat (cooling the surrounding) without subsequent heating under an electric pulse. Here, we show that such an EC material can be realized in a properly designed hybrid normal ferroelectric/relaxor ferroelectric polymer blend in which the normal ferroelectric component induces dipole ordering in the relaxor polymer in the poled state, which can be switched to a de-poled state by an external field. More importantly, the de-poled state can be maintained by the relaxor component when the de-poling field is removed. Consequently, the hybrid blend exhibits a large cooling (an isothermal entropy change ΔS = 11.5 J kg−1 K−1) without the subsequent heating upon the application of an electric pulse.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 04, 2016
- Source ID
- 10.1063/1.4944776
Entities
People
- Long-Qing Chen
- Qiming Zhang
- Tian Zhang
- Tiannan Yang
- Xiaoshi Qian
Organizations
- Army Research Office
- National Science Foundation
- Pennsylvania State University
- United States Department of Energy