Current-density dependence of the charge-ordering gap in the organic salt θ-(BEDT-TTF) 2CsM(SCN) 4 (M = Zn, Co, and Co 0.7Zn 0.3)

Fumiaki Sawano; Tomohiro Suko; Taichi S. Inada; Shuichi Tasaki; Ichiro Terasaki; Hatsumi Mori; Takehiko Mori; Yoshio Nogami; Naoshi Ikeda; Masashi Watanabe; Yukio Noda

doi:10.1143/JPSJ.78.024714

Current-density dependence of the charge-ordering gap in the organic salt θ-(BEDT-TTF) ₂CsM(SCN) ₄ (M = Zn, Co, and Co _0.7Zn _0.3)

Fumiaki Sawano, Tomohiro Suko, Taichi S. Inada, Shuichi Tasaki, Ichiro Terasaki, Hatsumi Mori, Takehiko Mori, Yoshio Nogami, Naoshi Ikeda, Masashi Watanabe, Yukio Noda

School of Science

Research output: Contribution to journal › Article › peer-review

15 Citations (Scopus)

Abstract

We have measured and analyzed the resistivity and voltage-current characteristics of the charge-ordered organic salt θ-(BEDT-TTF) ₂CsM(SCN) ₄ (M = Zn, Co, and Co _0.7Zn _0.3). At 4.3 K, all the samples show giant nonlinear conduction, in which the c-axis resistivity markedly decreases with external current by a factor of 10 against a small electric field of 1 V/cm. The temperature dependence of the resistivity is well described by an activation law, the activation energy of which is evaluated to be 2 meV in the lowcurrent limit, and linearly decreases with external current. The activation energy and x-ray intensity near q ₂ = (0, k, 1/2) are found to show the same dependence on current density. This coincidence strongly suggests that the energy gap of the charge order indexed by q ₂ is an order parameter of this phenomenon.

Original language	English
Article number	024714
Journal	journal of the physical society of japan
Volume	78
Issue number	2
DOIs	https://doi.org/10.1143/JPSJ.78.024714
Publication status	Published - Feb 2009

Keywords

BEDT-TTF
Charge ordering
Nonlinear conduction x-ray diffraction
Organic conductor

ASJC Scopus subject areas

Physics and Astronomy(all)

Access to Document

10.1143/JPSJ.78.024714

Cite this

Sawano, F., Suko, T., Inada, T. S., Tasaki, S., Terasaki, I., Mori, H., Mori, T., Nogami, Y., Ikeda, N., Watanabe, M., & Noda, Y. (2009). Current-density dependence of the charge-ordering gap in the organic salt θ-(BEDT-TTF) ₂CsM(SCN) ₄ (M = Zn, Co, and Co _0.7Zn _0.3). journal of the physical society of japan, 78(2), Article 024714. https://doi.org/10.1143/JPSJ.78.024714

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abstract = "We have measured and analyzed the resistivity and voltage-current characteristics of the charge-ordered organic salt θ-(BEDT-TTF) 2CsM(SCN) 4 (M = Zn, Co, and Co 0.7Zn 0.3). At 4.3 K, all the samples show giant nonlinear conduction, in which the c-axis resistivity markedly decreases with external current by a factor of 10 against a small electric field of 1 V/cm. The temperature dependence of the resistivity is well described by an activation law, the activation energy of which is evaluated to be 2 meV in the lowcurrent limit, and linearly decreases with external current. The activation energy and x-ray intensity near q 2 = (0, k, 1/2) are found to show the same dependence on current density. This coincidence strongly suggests that the energy gap of the charge order indexed by q 2 is an order parameter of this phenomenon.",

keywords = "BEDT-TTF, Charge ordering, Nonlinear conduction x-ray diffraction, Organic conductor",

author = "Fumiaki Sawano and Tomohiro Suko and Inada, {Taichi S.} and Shuichi Tasaki and Ichiro Terasaki and Hatsumi Mori and Takehiko Mori and Yoshio Nogami and Naoshi Ikeda and Masashi Watanabe and Yukio Noda",

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doi = "10.1143/JPSJ.78.024714",

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T1 - Current-density dependence of the charge-ordering gap in the organic salt θ-(BEDT-TTF) 2CsM(SCN) 4 (M = Zn, Co, and Co 0.7Zn 0.3)

AU - Sawano, Fumiaki

AU - Suko, Tomohiro

AU - Inada, Taichi S.

AU - Tasaki, Shuichi

AU - Terasaki, Ichiro

AU - Mori, Hatsumi

AU - Mori, Takehiko

AU - Nogami, Yoshio

AU - Ikeda, Naoshi

AU - Watanabe, Masashi

AU - Noda, Yukio

PY - 2009/2

Y1 - 2009/2

N2 - We have measured and analyzed the resistivity and voltage-current characteristics of the charge-ordered organic salt θ-(BEDT-TTF) 2CsM(SCN) 4 (M = Zn, Co, and Co 0.7Zn 0.3). At 4.3 K, all the samples show giant nonlinear conduction, in which the c-axis resistivity markedly decreases with external current by a factor of 10 against a small electric field of 1 V/cm. The temperature dependence of the resistivity is well described by an activation law, the activation energy of which is evaluated to be 2 meV in the lowcurrent limit, and linearly decreases with external current. The activation energy and x-ray intensity near q 2 = (0, k, 1/2) are found to show the same dependence on current density. This coincidence strongly suggests that the energy gap of the charge order indexed by q 2 is an order parameter of this phenomenon.

AB - We have measured and analyzed the resistivity and voltage-current characteristics of the charge-ordered organic salt θ-(BEDT-TTF) 2CsM(SCN) 4 (M = Zn, Co, and Co 0.7Zn 0.3). At 4.3 K, all the samples show giant nonlinear conduction, in which the c-axis resistivity markedly decreases with external current by a factor of 10 against a small electric field of 1 V/cm. The temperature dependence of the resistivity is well described by an activation law, the activation energy of which is evaluated to be 2 meV in the lowcurrent limit, and linearly decreases with external current. The activation energy and x-ray intensity near q 2 = (0, k, 1/2) are found to show the same dependence on current density. This coincidence strongly suggests that the energy gap of the charge order indexed by q 2 is an order parameter of this phenomenon.

KW - BEDT-TTF

KW - Charge ordering

KW - Nonlinear conduction x-ray diffraction

KW - Organic conductor

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