Structure and ferroelectric properties of P(VDF-TrFE) films prepared under different conditions - Effect of filtration of the copolymer solution

作     者：B.Ploss D.Smykalla S.Engel 

作者机构：Department of SciTecUniversity for Applied Sciences Jena07745 JenaGermany Faculty of Chemistry and Earth SciencesFriedrich-Schiller-University Jena07745 JenaGermany 

出 版 物：《Journal of Advanced Dielectrics》 (先进电介质学报（英文）)

年 卷 期：2023年第13卷第4期

页      面：48-51页

学科分类：07[理学] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

主　　题：P(VDF-TrFE) ferroelectric polymer structure 

摘      要：Vinylidene fluoride-trifluoroethylene copolymer films of molar ratio 70/30 with thickness of about 1μm have been deposited from solution in ethyl methyl ketone to a glass substrate with an aluminum electrode by spin *** solution has been filtrated through a PTFE membrane filter with pore size 0.2μm directly before spin coating or it has been used as is(unfiltrated).After deposition of a top electrode,the samples have been polarized by hysteresis loops with an electric field amplitude of about 100 V/μ*** samples,annealed at temperature 145°C for 3 h,a high remanent polarization of about 7.5μC/cm2 has been achieved,with­out significant differences between samples fabricated of filtrated or unfiltrated *** lamella are growing in films fabricated of filtrated solution when they are heated above the melting temperature to 159°C for 3 min before the further annealing process at 145°*** films show substantially lower remanent polarization below 4μC/*** images recorded with a pyroelectric laser scanning microscope show that the spherulites have very small pyroelectric activity,i.e.,the spherulites consist of flat-on *** contrast,no spherulitic lamella are growing in films fabricated of unfiltrated solution heated above the melting temperature,melted and annealed under the same *** explanation for this observation is that filtrating changes the structure of the copolymer in solution from polymer coil to *** rods deposited on a substrate will crystallize in flat-on lamella when heated above the melting temperature,in contrast to copolymer coils which crystallize in edge-on lamella.