External electric field dependence of the structure of the electric double layer at an ionic liquid/Au interface

Yamamoto, Ryōichi; Morisaki, Hazuki; Sakata, Osami; Shimotani, Hidekazu; Yuan, Huatang; Iwasa, Yoshihiro; Kimura, T.; Wakabayashi, Yusuke

doi:10.1063/1.4742920

Cited by 73 publications

(72 citation statements)

References 28 publications

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“…In addition, d EDL /κ EDL = 0.10±0.02 nm is determined from the intercept. Assuming that d EDL ≈ 1 nm, 22 κ EDL is evaluated to be ∼10, which shows agreement with other report using EDL capacitors. 23 We note that the experimentally determined ε 0 S c /C decreases slightly when an additional (dc) voltage V G dc is applied, as shown in the inset of Fig.…”

Section: A Capacitance Measurementsupporting

confidence: 79%

Dielectric and magnetic characterizations of capacitor structures with an ionic liquid/MgO barrier and a ferromagnetic Pt electrode

et al. 2016

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The dielectric and magnetic properties of electric double layer (EDL) capacitor structures with a perpendicularly magnetized Pt/Co/Pt electrode and an insulating cap layer (MgO) are investigated. An electric field is applied through a mixed ionic liquid/MgO barrier to the surface of the top Pt layer, at which the magnetic moment is induced by the ferromagnetic proximity effect. The basic dielectric properties of the EDL capacitor are studied by varying the thickness of the MgO cap layer. The results indicate that the capacitance, i.e., the accumulated charge density at the Pt surface, is reduced with increasing the MgO thickness. From the MgO thickness dependence of the capacitance value, the effective dielectric constant of the ionic liquid is evaluated. Almost no electric field effect on the magnetic moment, the coercivity, or the Curie temperature is confirmed in the top Pt layer with the thickness of 1.3 nm, regardless of the presence or absence of the MgO cap layer, whereas the a clear change in the magnetic moment is observed when the top Pt layer is replaced by a Pd layer of 1.7 nm.

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Section: A Capacitance Measurementsupporting

confidence: 79%

Dielectric and magnetic characterizations of capacitor structures with an ionic liquid/MgO barrier and a ferromagnetic Pt electrode

et al. 2016

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“…Modifications to this theory to include the finite size of ions, successfully described some important properties of RTILs [5,6], and non-mean field theories suggested explanation to RTILs' unexpectedly high double layer capacitance [7,8]. However, we are still far from having a realistic theoretical picture of the RTIL/electrode interface.Recent experimental and computational studies show that RTILs can exhibit charge-separated (cation-anion) layered structures at charged interfaces [5,6,[9][10][11][12][13][14][15]. These results are not totally unexpected, considering that many liquids (including liquid metals [16], dielectric liquids [17], and even water [18]) are known to exhibit layering at the liquid/solid interface.…”

mentioning

confidence: 99%

Interfacial ionic ‘liquids’: connecting static and dynamic structures

Uysal

Zhou

Feng

et al. 2014

J. Phys.: Condens. Matter

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It is well known that room temperature ionic liquids (RTILs) often adopt a charge-separated layered structure, i.e. with alternating cation- and anion-rich layers, at electrified interfaces. However, the dynamic response of the layered structure to temporal variations in applied potential is not well understood. We used in situ, real-time x-ray reflectivity to study the potential-dependent electric double layer (EDL) structure of an imidazolium-based RTIL on charged epitaxial graphene during potential cycling as a function of temperature. The results suggest that the graphene-RTIL interfacial structure is bistable in which the EDL structure at any intermediate potential can be described by the combination of two extreme-potential structures whose proportions vary depending on the polarity and magnitude of the applied potential. This picture is supported by the EDL structures obtained by fully atomistic molecular dynamics simulations at various static potentials. The potential-driven transition between the two structures is characterized by an increasing width but with an approximately fixed hysteresis magnitude as a function of temperature. The results are consistent with the coexistence of distinct anion- and cation-adsorbed structures separated by an energy barrier (∼0.15 eV).

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“…It shows clear oscillation as a function of the scattering angle. This is originated from the formation of the EDL at the Au/IL interface [14]. The IL used was EMI-TFSI, whose cation (EMI) is made of C, N and H, while the anion (TFSI) contains F and S, thus the electron density of the anion is higher than that of the cation.…”

Section: Results and Analysismentioning

confidence: 99%

“…† Corresponding author: wakabayashi@mp.es.osaka-u.ac.jp nique, it would give little disturbance on the external electric field effect on the interfacial structure. For example, electric double layer (EDL) formed at the interface between gold and an ionic liquid (IL) interface is observed by this method [14]. The external voltage effect on the interfacial structure is usually small, and the differential detection is found to be useful.…”

Section: Introductionmentioning

confidence: 99%

Structural Switching of Self-Assembled Monolayer by External Electric Field

Fujii

Sasaki

Wakabayashi

et al. 2018

e-J. Surf. Sci. Nanotech.

Self Cite

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Self-assembled monolayers (SAMs) are used for adjusting the work function of metal electrodes in organic devices. Since the energy level difference between the HOMO or LUMO and the work function affects the electron injection through the metal-organic interfaces, fine tuning of the work function is of importance. To control the work function from external environment, external large electric field on low-density SAMs is reported to be effective. In order to obtain a direct evidence for the structural switching of the SAM, X-ray reflectivity measurements were performed. The result shows that the molecular tilting of 10• is induced by the external voltage application.

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External electric field dependence of the structure of the electric double layer at an ionic liquid/Au interface

Cited by 73 publications

References 28 publications

Dielectric and magnetic characterizations of capacitor structures with an ionic liquid/MgO barrier and a ferromagnetic Pt electrode

Dielectric and magnetic characterizations of capacitor structures with an ionic liquid/MgO barrier and a ferromagnetic Pt electrode

Interfacial ionic ‘liquids’: connecting static and dynamic structures

Structural Switching of Self-Assembled Monolayer by External Electric Field

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