Relaxor ferroelectric polymer exhibits ultrahigh electromechanical coupling at low electric field

Abstract

Electromechanical (EM) coupling—the conversion of energy between electric and mechanical forms—in ferroelectrics has been used for a broad range of applications. Ferroelectric polymers have weak EM coupling that severely limits their usefulness for applications. We introduced a small amount of fluorinated alkyne (FA) monomers (<2 mol %) in relaxor ferroelectric poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (PVDF-TrFE-CFE) terpolymer that markedly enhances the polarization change with strong EM coupling while suppressing other polarization changes that do not contribute to it. Under a low–dc bias field of 40 megavolts per meter, the relaxor tetrapolymer has an EM coupling factor ( k 33 ) of 88% and a piezoelectric coefficient ( d 33 ) >1000 picometers per volt. These values make this solution-processed polymer competitive with ceramic oxide piezoelectrics, with the potential for use in distinct applications.

Biferroelectricity of a homochiral organic molecule in both solid crystal and liquid crystal phases

“…The discovery of ferroelectricity in Rochelle salt opens up the history of ferroelectrics since 1920 7 . Ferroelectricity comes from the directional arrangement of electric dipoles, basically existing in the crystalline or semi-crystalline solid materials with polar symmetry, including inorganic crystals or ceramics 8 – 11 , molecular crystals 2 , 12 – 26 , and polymers 27 , 28 , rather than fluid phases. Although the liquid crystal (LC) was discovered as early as 1888 by the botanist Friedrich Reinitzer 29 , which has revolutionized the display industries 30 – 33 , the first ferroelectric liquid crystal (FLC) p-decyloxybenzylidene p’-amino 2-methyl butyl cinnamate (DOBAMBC) was not discovered until 1975 by Meyer et al 34 .…”

Polymer Nanocomposite Dielectrics: Understanding the Matrix/Particle Interface

“…Therefore, it will be of interest to implement characterizations under high electric fields, in which the information on interface that is hardly detectable under low-field characterizations may be revealed. For instance, the polymer can be monitored using XRD while an electric field is applied onto the sample, where the strain in the crystalline part and even an entirely different XRD pattern can be found under the high electrical field. In addition, the dielectric constant can be investigated under high electric fields by using DC-biased BDS.…”

Ferroelectricity in organic materials: from materials characteristics tode novodesign

“…10 Very recently, a ferroelectric polymer have shown an exceptionally high electromechanical coupling at a low electric field. 11 However, the number of ferroelectrics in low-molecular weight organic compounds is rare. As shown in Fig.…”