Gigantic Pockels effect in water within the electric double layer
| Project/Area Number |
21540326
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Condensed matter physics I
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| Research Institution | Tokyo University of Science |
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Principal Investigator |
TOKUNAGA Eiji 東京理科大学, 大学院・理学研究科・物理学専攻, 准教授 (70242170)
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| Project Period (FY) |
2009 – 2011
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| Project Status |
Completed (Fiscal Year 2011)
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| Budget Amount *help |
¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2011: ¥260,000 (Direct Cost: ¥200,000、Indirect Cost: ¥60,000)
Fiscal Year 2010: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2009: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
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| Keywords | 光物性 / 表面・界面 / 水 / ポッケルス効果 / 電気光学効果 / 電気二重層 / 偏向スイッチング / Sagnac干渉計 / ITO / Pt / GaN / TiO2 / DMSO / メタノール |
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| Research Abstract |
The Pockels coefficients of aqueous electrolyte solution within the electric double layer(EDL) were determined for various electrode materials at the interface as r13=(0.40-0.53)×100 pm/V for TiO2 and r13=0.18×100 pm/V for GaN(0.1M NaCl solution). These values are smaller than that for ITO, r13=(2.0±0.3)×100 pm/V. The Pockels effect on the ITO electrode for polar organic solvents other than water is also studied to find that methanol and ethanol have large Pockels coefficients comparable to water(0.1M LiCl solution). Methanol has the largest coefficient, followed in order by water, ethanol, and DMSO. To be summarized in the magnitude of the Pockels effect, oxide is superior to nitride about the electrode dependence, and protonic solvent is superior to aprotonic solvent(DMSO) about the solvent dependence. These results suggest that broken inversion symmetry due to interaction of solvent molecules with the electrode surface through the hydrogen bonds is responsible for the Pockels effect.
Further, deflection of a laser beam in response to an electric field was detected with a Sagnac interferometer. A laser beam was aligned to travel between two electrodes immersed in aqueous electrolyte solution. When the alternating electric field was applied perpendicular to the beam axis, the direction of the beam deflection was switched synchronously with the field alternation as expected for the Pockels effect. Broken inversion symmetry is prerequisite to the linear electrooptic effect, but surprisingly the effect was observed even when the laser beam travels through the bulk water a few millimeters away from the electrode surface. The Pockels coefficient in the bulk water is one order of magnitude smaller than that in water within the EDL, but it is still comparable to that for LiNbO3.
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Report
(4 results)
Research Products
(20 results)
