Dielectric and Ferroelectric Hysteresis loop Measurements for Thin Organic Films by Non-contact Electrode Method

采用非接触电极法测量有机薄膜的介电和铁电磁滞回线

• 批准号: 04650029
• 负责人: NAGAMORI Tomomi
• 金额: $ 1.15万
• 依托单位: Ariake National College of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04650029/
• 关键词: Ultrathin Films; Evaporation; Dielectric Constants; Phase Transition; D-E Hysteresis Measurements; Structural Control; Ferroelectricity; FT-IR; 蒸着; VDF; TrFE; 分子配向; FT-IR

Dielectric and ferroelectric hysteresis loop(D-E) measurements were conducted for evaporated organic thin films by utilizing a newly developed sample cell with non-contact electrode, showing the structure of the cell. The performance was confirmed for the spin coated film sample of vinylidene fluoride-trifluoroethylene (VDF/TrFE) copolymer. Then, for evaporated thin films of VDF/TrFE copolymer, the characteristic were investigated, exhibiting a ferroelectric nature in dielectric measurement and a hysteresis loop in D-E measurement when an electric field of 30 MV/m was applied during the evaporation process. Moreover, evaporated films of newly synthesized VDF telomer for using in polymerization of PVDF also were measured.Fourier Transform-IR (FT-IR) spectroscopic measurements were conducted on VDF/TrFE copolymers with 73mol.% VDF content in order to investigate the ferro-to paraelectric phase transitions in evaporated and spin-coated thin films. Upon heating and cooling, several IR band … More s revealed the considerable changes in the wave-numbers with a thermal hysteresis in the evaporated thin film sample as well as spin coated films, reflecting the first order ferroelectric phase transition. Moreover, the degree of the changes differed depending on the kinds of substrates, suggesting that the interaction between the sample and the substrate affects the occurrence of the transitions.A newly synthesized low molecular weight sample, named vinylidene fluoride telomer (VDF telomer), was employed as a sample because a previous study for a poly (vinylidene fluoride) sample revealed that the pyrolysis of such a polymeric sample took place during the evaporation, causing the lowering of its crystallinity. The molecular orientation and phase transition behavior of the VDF telomer evaporated films were evaluated by means of an energy dispersiv-type total reflection and symmetrical reflection X-ray diffractometer and FT-IR spectroscopy. The results showed that the evaporated films formed a layred structure, were consisted of form II crystals with TGTG'chain segments and the molecular axis in the films was perpendicular to the substrate. Upon heating process, it was also observed the occurrence of the solid-solid phase transition at about 70ﾟC, where the crystals changed from form II to form III, and then the layred structure disappeared above 90ﾟC. Less

利用新开发的非接触电极样品池对蒸发有机薄膜进行了介电和铁电磁滞回线（D-E）测量，显示了样品池的结构。偏二氟乙烯-三氟乙烯 (VDF/TrFE) 共聚物的旋涂薄膜样品的性能得到了证实。然后，对于VDF/TrFE共聚物的蒸发薄膜，研究了其特性，当在蒸发过程中施加30 MV/m的电场时，在介电测量中表现出铁电性质，在D-E测量中表现出磁滞回线。此外，还测量了用于PVDF聚合的新合成的VDF调聚物的蒸发薄膜。对VDF含量为73mol.%的VDF/TrFE共聚物进行了傅里叶变换红外(FT-IR)光谱测量，以研究蒸发和旋涂薄膜中的铁-顺电相变。在加热和冷却时，几个红外波段揭示了蒸发薄膜样品和旋涂薄膜中波数的显着变化以及热滞后，反映了一级铁电相变。此外，变化的程度根据底物的种类而不同，这表明样品和底物之间的相互作用影响了转变的发生。采用一种新合成的低分子量样品，称为偏二氟乙烯调聚物（VDF调聚物）作为样品，因为之前对聚偏二氟乙烯样品的研究表明，这种偏二氟乙烯调聚物的热解 聚合物样品在蒸发过程中发生，导致其结晶度降低。采用能量色散型全反射和对称反射X射线衍射仪和FT-IR光谱仪对VDF调聚物蒸发膜的分子取向和相变行为进行了评价。结果表明，蒸镀薄膜形成层状结构，由具有TGTG'链段的II型晶体组成，薄膜中的分子轴垂直于基底。在加热过程中，还观察到在70℃左右发生固-固相变，晶体从II型转变为III型，然后层状结构在90℃以上消失。较少的

项目成果

Katsunori Ishizaki Toshihisa Horiuchi Kazumi Matsushige: "Fourier transform IR study on structural evaluation of evaporated organic thin films Part1.Changes in molecular orientation of n-paraffins by heat treatment" Thin Solid Films. 214. 99-103 (1992)

Katsunori Ishizaki Toshihisa Horiuchi Kazumi Matsushige：“蒸发有机薄膜结构评估的傅里叶变换红外研究第 1 部分。热处理导致正链烷烃分子取向的变化”薄膜固体。

Katsunori ISHIZAKI: "Study on Phase Transition in Vinylidene Fluoride Telomer" Research Reports of the Ariake National College of Technology No.30. 23 (1994)

石崎克典：《偏二氟乙烯调聚物的相变研究》有明工业大学研究报告第30期。

Yuji YOSHIDA: "Study on Molecular Orientation and Phase Transition Behavior in Vinylidene Fluoride Telomer Evaporated Films" Technology Reports of Kyushu University. Vol.66, No.4. 199 (1993)

Yuji YOSHIDA：《偏二氟乙烯调聚物蒸发薄膜中的分子取向和相变行为研究》九州大学科技报告。

Y.Yoshida: "Molecular Orientation and Phase Transition in Vinyliden Fluoride Telomer Evaporated Thin Films" Reports on Progress in Polymer Physics in Japan. 36. 225-228 (1993)

Y.Yoshida：“偏氟乙烯调聚物蒸发薄膜中的分子取向和相变”报道了日本高分子物理学的进展。

Tomomi NAGAMORI Toshihisa HORIUCHI Kazuhiro HARA Kazumi MATSUSHIGE: "Dielectric and Ferroelectric Hysteresis Loop Measurements for Ultrathin VDF/TrFE Copolymer Films Under Electric Field" JAPANESE JOURNAL OF APPLIED PHYSICS. 31. 1407-1408 (1992)

Tomomi NAGAMORI Toshihisa HORIUCHI Kazuhiro HARA Kazumi MATSUSHIGE：“电场下超薄 VDF/TrFE 共聚物薄膜的介电和铁电磁滞回线测量”日本应用物理学杂志。