Anomalous ferroelectricity in P(VDF70-TrFE30). Issue 1 (4th April 2017)

• Record Type: Journal Article
• Authors: Mehner, Erik; Jachalke, Sven; Hanzig, Juliane; Leisegang, Tilmann; Stöcker, Hartmut; Meyer, Dirk C.
• Is Part Of: Ferroelectrics. Volume 510:Issue 1(2017)
• Page Start: 132
• Page End: 151
• Publication Date: 2017-04-04
• Subjects: Pyroelectricity -- ferroelectricity -- phase transition -- copolymer -- vinylidene fluoride -- trifluoroethylene -- X-ray diffraction -- flexoelectricity -- differential scanning calorimetry; Ferroelectricity -- Periodicals; Ferroelectric crystals -- Periodicals; 537
• DOI: 10.1080/00150193.2017.1328249
• Languages: English
• ISSNs: 0015-0193

Abstract

ABSTRACT: The ferroelectric phase transition of copolymers of vinylidene fluoride (VDF) with trifluoroethylene (TrFE) is well known and related to conformational changes in the polymer chain. Contrary to the expected paraelectric behaviour in the high temperature phase a pyroelectric investigation of the phase transition in the range from 0°C to 130°C combined with X-ray diffraction indicate the copolymer as ferroelectric when prepared and polarised in the high-temperature phase. Based on this finding the orthorhombic space-group Fmm 2 is proposed for the polar high-temperature phase. Above the Curie temperature the material exhibits pyroelectricity with inverted sign, whose origin is interpreted as flexoelectricity.