Temperature-Pressure Phase Diagram in TTF-TCNQ : Strong Suppression of Charge-Density-Wave State under Extremely High Pressure(Condensed matter: electronic structure and electrical, magnetic, and optical properties)
Temperature-Pressure Phase Diagram in TTF-TCNQ : Strong Suppression of Charge-Density-Wave State under Extremely High Pressure(Condensed matter: electronic structure and electrical, magnetic, and optical properties)
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DOI：
10.1143/jpsj.76.033701
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发表时间：
2007-02
影响因子：
1.7
通讯作者：
S. Yasuzuka;K. Murata;Taro Arimoto;R. Kato
中科院分区：
文献类型：
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作者：
S. Yasuzuka;K. Murata;Taro Arimoto;R. Kato
我们用六面顶砧装置测量了有机导体TTF-TCNQ在高达8.0GPa的高压下的电阻率。在3 GPa以下，电荷密度波（CDW）转变温度T CDW的压力依赖性与之前的结果一致，除了在1 GPa左右观察到“49 K转变”之外。在3GPa以上，T CDW随压力的增加而减小，但CDW状态甚至在8.0GPa下仍然存在。在8.0GPa下，在T_（CDW）= 31 K的CDW转变后，电阻率在25 K以下表现为金属行为。抑制的起源进行了讨论，在不完善的嵌套源于链间传输积分的增加，从三阶可扩展性的显着偏差，以及TTF和TCNQ堆栈的带宽加宽。CDW相的完全抑制预计在9 GPa附近。
We have measured the resistivity of the organic conductor TTF-TCNQ under high pressure up to 8.0 GPa using a cubic anvil apparatus. Below 3 GPa, the pressure dependence of the charge-density-wave (CDW) transition temperature, T CDW , is consistent with previous results, except for the observation of the “49 K-transition” at around 1 GPa. Above 3 GPa, T CDW decreases with increasing pressure but the CDW state survives even at 8.0 GPa. At 8.0 GPa, however, the resistivity shows metallic behavior below 25 K after the CDW transition with T CDW = 31 K. The origin of suppression is discussed in terms of the imperfect nesting originating from the increase in the interchain transfer integral, the significant deviation from the third-order commensurability, as well as the bandwidth broadening for both TTF and TCNQ stacks. The complete suppression of the CDW phase is expected near 9 GPa.