Structural study on ferroelectric phase transition of vinylidene fluoride-trifluoroethylene copolymers (III) dependence of transitional behavior on VDF molar content

Tashiro, Kohji; Takano, Koji; Kobayashi, Masamichi; Chatani, Yôzô; Tadokoro, Hiroyuki

doi:10.1080/00150198408012770

Cited by 282 publications

(147 citation statements)

References 27 publications

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“…The spectra shown in Figs. 1-3 are similar to the ␤ phase spectra obtained from the copolymer solution-cast films 18 and vacuumevaporated films. 15 Seven main peaks are evident at 1428, 1403, 1290, 1182, 1070, 886, and 850 cm Ϫ1 .…”

Section: A Conformation and Vibrational Mode Orientationsupporting

confidence: 68%

“…2͑b͒ and 3, we can see that the in-plane intensity of the peak at 1403 cm Ϫ1 is greater than the out-of-plane intensity and decreases in intensity with the increasing incident angle, indicating that the transition dipole of this mode is predominantly in the film plane. According to Tashiro 8 and Tashiro, Takano, and Kobayashi 18 this mode combines the CC out-ofphase symmetrical stretching and CH 2 wagging motions, which are along the chain direction (B 1 ) for the ␤ phase all-trans conformation, so we can conclude that the polymer chains of the LB films are mostly parallel to the film plane, with a random in-plane orientation.…”

mentioning

confidence: 86%

“…Experimental studies on the PVDF/TrFE ͑73/27͒ copolymer by Tashiro and Kobayashi in 1994 15 showed that poling the film increased the normal component of the 850, 1290, and 1428 cm Ϫ1 modes, showing A 1 character, and decreased the normal component of the 886 and 1182 cm Ϫ1 modes, showing B 2 character for these two modes. 15,18 There are several reasons that the poling data might have been misleading. First, recall that these two peaks could come from three crystalline phases as well as amorphous material in the solvent-formed films.…”

mentioning

confidence: 99%

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Infrared spectroscopic ellipsometry study of vinylidene fluoride (70%)-trifluoroethylene (30%) copolymer Langmuir–Blodgett films

Bai

Poulsen

Sorokin

et al. 2003

Journal of Applied Physics

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Bai, Mengjun; Poulsen, Matt; Sorokin, A.V.; Ducharme, Stephen; Herzinger, C.M.; and Fridkin, V.M., "Infrared spectroscopic ellipsometry study of vinylidene fluoride (70%)-trifluoroethylene (30%) copolymer Langmuir-Blodgett films" (2003 We report the studies of the molecular conformation and chain orientations through characterization of the vibrational modes in crystalline Langmuir-Blodgett films of the polyvinylidene fluoride/ trifluoroethylene copolymer. The infrared spectra obtained by polarized reflectometry and ellipsometry showed that the ferroelectric phase has predominantly all-trans conformation and the paraelectric phase has predominantly alternating trans-gauche conformation, as in solvent-formed films of the same copolymer. The results showed that the polymer chains are predominantly parallel to the film plane with a random in-plane orientation and most of the ferroelectric phase vibrational mode behaviors are consistent with the published mode assignments. The ferroelectric phase optical dispersion curves in the infrared range were extracted from the data analysis based on a uniaxial model.

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Section: A Conformation and Vibrational Mode Orientationsupporting

confidence: 68%

mentioning

confidence: 86%

mentioning

confidence: 99%

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Infrared spectroscopic ellipsometry study of vinylidene fluoride (70%)-trifluoroethylene (30%) copolymer Langmuir–Blodgett films

Bai

Poulsen

Sorokin

et al. 2003

Journal of Applied Physics

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“…In the crystalline b-phase, molecules tend to pack parallel to each other forming a quasi-hexagonal orthorhombic structure with "m2m" point group. 26 For PVDF-TrFE, the piezoelectric tensor d …”

Section: -25mentioning

confidence: 99%

Orientational imaging in polar polymers by piezoresponse force microscopy

Sharma

Poddar

et al. 2011

Journal of Applied Physics

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We report orientational imaging of the polarization distribution in nanostructured ferroelectric copolymer of polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) and collagen fibrils using vertical and lateral modes of piezoresponse force microscopy (PFM). In PVDF-TrFE, detection of azimuthal variations in the lateral PFM signal is attributed to the alignment of the molecular chains along different directions. Local switching in PVDF-TrFE is shown to proceed via 120 or 180 rotation of dipoles around the molecular chain, depending upon the strength of the applied electric field. Analysis of the vertical and lateral PFM signals in collagen reveals polar anisotropy of the electromechanical properties along the axes of the fibrils. The surface plots of the piezoelectric response are constructed for both materials based on their piezoelectric tensors and are shown to be consistent with the observed vertical and lateral PFM maps.

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“…Therefore, most studies of ferroelectric properties were conducted on the copolymers P(VDF ± TrFE), random copolymers of vinylidene fluoride and trifluoroethylene monomers with structure (CH 2 ± CF 2 ) n ± (CHF ± CF 2 ) m . The copolymers with 50% or less TrFE are ferroelectric, though with reduced polarization and transition temperatures, because some of the hydrogen atoms are replaced with fluorine, reducing the net dipole moment of the polymer chains [58]. Spun polymeric films reveal rapid (about 1 ms) ferroelectric switching, which depends on the electric field and film thickness [41].…”

Section: Ferroelectric Polymers: Vinylidene Fluoride Copolymersmentioning

confidence: 99%

Two-dimensional ferroelectrics

Blinov¹,

Fridkin²,

Palto³

et al. 2000

Phys.-Usp.

136

100

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Blinov, L. M.; Fridkin, V. M.; Palto, S.P.; Bune, A. V.; Dowben, Peter A.; and Ducharme, Stephen, "Two-Dimensional Ferroelectrics" (2000). Abstract. The investigation of the finite-size effect in ferroelectric crystals and films has been limited by the experimental conditions. The smallest demonstrated ferroelectric crystals had a diameter of $ 200 A and the thinnest ferroelectric films were $ 200 A thick, macroscopic sizes on an atomic scale. Langmuir ± Blodgett deposition of films one monolayer at a time has produced high quality ferroelectric films as thin as 10 A, made from polyvinylidene fluoride and its copolymers. These ultrathin films permitted the ultimate investigation of finite-size effects on the atomic thickness scale. Langmuir ± Blodgett films also revealed the fundamental two-dimensional character of ferroelectricity in these materials by demonstrating that there is no so-called critical thickness; films as thin as two monolayers (1 nm) are ferroelectric, with a transition temperature near that of the bulk material. The films exhibit all the main properties of ferroelectricity with a first-order ferroelectric ± paraelectric phase transition: polarization hysteresis (switching); the jump in spontaneous polarization at the phase transition temperature; thermal hysteresis in the polarization; the increase in the transition temperature with applied field; double hysteresis above the phase transition temperature; and the existence of the ferroelectric critical point. The films also exhibit a new phase transition associated with the twodimensional layers.

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Structural study on ferroelectric phase transition of vinylidene fluoride-trifluoroethylene copolymers (III) dependence of transitional behavior on VDF molar content

Cited by 282 publications

References 27 publications

Infrared spectroscopic ellipsometry study of vinylidene fluoride (70%)-trifluoroethylene (30%) copolymer Langmuir–Blodgett films

Infrared spectroscopic ellipsometry study of vinylidene fluoride (70%)-trifluoroethylene (30%) copolymer Langmuir–Blodgett films

Orientational imaging in polar polymers by piezoresponse force microscopy

Two-dimensional ferroelectrics

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