Investigation of Ferroelectric Properties of Vinylidene Fluoride Oligomer Evaporated Films

2002 ◽  
Vol 748 ◽  
Author(s):  
K. Noda ◽  
K. Ishida ◽  
K. Mochizuki ◽  
A. Kubono ◽  
T. Horiuchi ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Vinylidene Fluoride ◽  
Ferroelectric Phase ◽  
Ferroelectric Properties ◽  
Liquid Nitrogen Temperature ◽  
Polarization Reversal ◽  
Phase Form ◽  
Atomic Force ◽  
Oriented Parallel ◽  
Substrate Surfaces

ABSTRACTStructures and electrical properties of newly synthesized vinylidene fluoride (VDF) oligomer [CF3(CH2CF2)17I] films evaporated onto various substrates around liquid nitrogen temperature were investigated. As a result, the VDF oligomer films were mainly formed with ferroelectric phase (form I) crystals and the molecular chains were oriented parallel to the substrate surfaces regardless of both the kind of the substrates and the thickness of the VDF oligomer films. In addition to these properties, the VDF oligomer films showed polarization reversal due to 180° rotation of the polar VDF oligomer molecules according to the applied voltages. This ferroelectric behavior was verified by local poling and piezoresponse measurements with an atomic force microscope, and by measurements of D-E hysteresis curves.

Development of Nonvolatile Memory using Well-Ordered Ferroelectric Linear Molecules

2004 ◽  
Vol 830 ◽  
Author(s):  
Kenji Ishida ◽  
Kazunari Katsumoto ◽  
Shuichiro Kuwajima ◽  
Toshihisa Horiuchi ◽  
Hirofumi Yamada ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Nonvolatile Memory ◽  
Remanent Polarization ◽  
Vinylidene Fluoride ◽  
Ferroelectric Phase ◽  
Low Cost ◽  
Ferroelectric Properties ◽  
Low Molecular Weight ◽  
Polarization Reversal ◽  
Linear Molecules

ABSTRACTFerroelectric vinylidene fluoride (VDF) molecular films were fabricated by simple vacuum evaporation method, and the ferroelectric properties and its fatigue were investigated. Formation of ferroelectric phase in VDF oligomer with low molecular weight is favored at low substrate temperature around -150°C. The well-ordered VDF oligomer thin films exhibit a lager value of remanent polarization(130mC/m2) than that of Poly(VDF). Fatigues of polarization reversal can be performed over 10∧5 cycles. The VDF oligomer films can be one of candidates for disposable nonvolatile memory with unique features such as flexible, wide areas and low cost processing.

Ferroelectric Properties and Crystal Structure of YBa2Cu3O7/BaxSr(1−x)TiO3 Heterostructures

1997 ◽  
Vol 493 ◽  
Author(s):  
CH. Schwan ◽  
F. Martin ◽  
G. Jakob ◽  
J. C. Martinez ◽  
H. Adrian
Keyword(s):  
Domain Walls ◽  
Ferroelectric Phase ◽  
Ferroelectric Properties ◽  
Rf Sputtering ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
Weiss Temperature ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTEpitaxial YBa2Cu3O7/Ba0.5Sr0.5TiO3 (YBCO/BST) and YBCO/BaTiO3 (BTO) heterostructures were prepared by dc and rf sputtering on SrTiO3 and MgO substrates. The YBCO/BTO bilayers exhibit an inductive superconducting transition temperature of 85 K and the ferroelectric phase transition of BST shows a Curie-Weiss temperature of 310 K. Microstructure was investigated by x-ray-diffraction and atomic force microscopy. In this work we also studied the insulator's conductivity and the contribution of domain walls to permittivity.

scholarly journals Composite Ferroelectric Membranes Based on Vinylidene Fluoride-Tetrafluoroethylene Copolymer and Polyvinylpyrrolidone for Wound Healing

Membranes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Tamara S. Tverdokhlebova ◽  
Ludmila S. Antipina ◽  
Valeriya L. Kudryavtseva ◽  
Ksenia S. Stankevich ◽  
Ilya M. Kolesnik ◽  
...  
Keyword(s):  
Wound Healing ◽  
Vinylidene Fluoride ◽  
Ferroelectric Properties ◽  
Composite Membranes ◽  
Modern Medicine ◽  
In Vivo Studies ◽  
Cytotoxic Effects ◽  
Complex Process ◽  
Purulent Wounds

Wound healing is a complex process and an ongoing challenge for modern medicine. Herein, we present the results of study of structure and properties of ferroelectric composite polymer membranes for wound healing. Membranes were fabricated by electrospinning from a solution of vinylidene fluoride/tetrafluoroethylene copolymer (VDF–TeFE) and polyvinylpyrrolidone (PVP) in dimethylformamide (DMF). The effects of the PVP content on the viscosity and conductivity of the spinning solution, DMF concentration, chemical composition, crystal structure, and conformation of VDF–TeFE macromolecules in the fabricated materials were studied. It was found that as PVP amount increased, the viscosity and conductivity of the spinning solutions decreased, resulting in thinner fibers. Using FTIR and XRD methods, it was shown that if the PVP content was lower than 50 wt %, the VDF–TeFE copolymer adopted a flat zigzag conformation (TTT conformation) and crystalline phases with ferroelectric properties were formed. Gas chromatography results indicated that an increase in the PVP concentration led to a higher residual amount of DMF in the material, causing cytotoxic effects on 3T3L1 fibroblasts. In vivo studies demonstrated that compared to classical gauze dressings impregnated with a solution of an antibacterial agent, ferroelectric composite membranes with 15 wt % PVP provided better conditions for the healing of purulent wounds.

scholarly journals Giant spontaneous polarization for enhanced ferroelectric properties of biaxially oriented poly(vinylidene fluoride) by mobile oriented amorphous fractions

2021 ◽  
Author(s):  
Guanchun Rui ◽  
Yanfei Huang ◽  
Xinyue Chen ◽  
Ruipeng Li ◽  
Dingrui Wang ◽  
...  
Keyword(s):  
Spontaneous Polarization ◽  
Vinylidene Fluoride ◽  
Ferroelectric Properties ◽  
Amorphous Fraction ◽  
Poly Vinylidene Fluoride

Oriented amorphous fraction in biaxially oriented poly(vinylidene fluoride) gives it significantly enhanced dielectric and ferroelectric properties.

Preparation and electrical properties of γ form poly(vinylidene fluoride) thin film by vapour deposition in the presence of an electric field

1991 ◽  
Vol 202 (2) ◽  
pp. 213-220 ◽  
Author(s):  
Akiyoshi Takeno ◽  
Norimasa Okui ◽  
Tetsuji Kitoh ◽  
Michiharu Muraoka ◽  
Susumu Umemoto ◽  
...  
Keyword(s):  
Thin Film ◽  
Electrical Properties ◽  
Electric Field ◽  
Vapour Deposition ◽  
Vinylidene Fluoride ◽  
Poly Vinylidene Fluoride

Ferroelectric properties and polarization reversal phenomena in nylon 11

1995 ◽  
Vol 171 (1) ◽  
pp. 329-338 ◽  
Author(s):  
Susumu Ikeda ◽  
Takao Saito ◽  
Makoto Nonomura ◽  
Tomonori Koda
Keyword(s):  
Ferroelectric Properties ◽  
Polarization Reversal ◽  
Nylon 11

SPM Characterization of Substrate Surfaces Prepared for Carbon-Related-Film Deposition

1999 ◽  
Vol 587 ◽  
Author(s):  
Kazumasa Narumi ◽  
Shunya Yamamoto ◽  
Hiroshi Naramoto
Keyword(s):  
Annealing Temperature ◽  
Temperature Characteristic ◽  
Film Deposition ◽  
Annealing Conditions ◽  
Atomic Force ◽  
Surface Steps ◽  
Order Of Magnitude ◽  
Reducing Environment ◽  
Substrate Surfaces

AbstractsVariation of surface steps on sapphire (0001) and (1120) substrates processed with thermal annealing in air or a reducing environment at 1000 to 1400°C for 1 to 10 hours were investigated with an atomic force microscope (AFM). The annealed (0001) surfaces consist of atomically smooth and large terraces and atomic-height steps, whose configurations strongly depend on annealing conditions. On the (1120) surfaces, where crystallographic misorientation is almost an order of magnitude larger than that of the (0001) surfaces, step height and terraces increase in size with the longer annealing time and higher annealing temperature. Characteristic step figures due to the symmetry of atomic arrangement were observed on the (0001) surface.

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