Novel Type of Career Generated System: Magnetic Investigations of TTF-Based Self-Doped Hydrogen-Bonding Conductor
Novel Type of Career Generated System: Magnetic Investigations of TTF-Based Self-Doped Hydrogen-Bonding Conductor
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DOI：
10.1143/jpsj.79.053701
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发表时间：
2010-05-01
影响因子：
1.7
通讯作者：
Ogura, Takashi
中科院分区：
文献类型：
--
作者：
Furukawa, Ko;Nakamura, Toshikazu;Ogura, Takashi
对有机导体（TTFCOO）[(NH4+1)(1-x)(NH3)(x)]进行了静态磁化率和高场电子自旋共振（ESR）测量。采用高频w波段（93.9817 GHz） ESR谱仪测定粉末样品的各向异性ESR参数。观测到的g张量主值和量子化学计算结果表明，观测到的自旋分布在类空穴TTF骨架上，TTFCOO主体部分变成中性自由基。自旋磁化率的温度依赖性与居里-魏斯项和活化型项拟合良好，在高温下活化型项占主导地位。高的自旋磁化率绝对值和极小的活化能δ表明（TTFCOO）[(NH4+1)(1-x)(NH3)(x)]中的准简并态是稳定的，尽管弱温度依赖的ESR线宽显示出局域特征。讨论了一种新的载流子生成方式——自掺杂。
Magnetic investigations, including static magnetic susceptibility and high-field electron spin resonance (ESR) measurements, were carried out for an organic conductor, (TTFCOO)[(NH4+1)(1-x)(NH3)(x)]. Anisotropic ESR parameters were determined for powder samples using a high-frequency W-band (93.9817 GHz) ESR spectrometer. The observed principal values of the g-tensor and quantum chemical calculation results indicate that the observed spin is distributed on quasi-hole-like TTF skeletons, and that the TTFCOO mainframe partially becomes a neutral radical. The temperature dependence of the spin susceptibility is well fitted with a Curie-Weiss term and an activation-type term, with the activation-type term dominant at high temperatures. The high absolute value of the spin susceptibility and the extremely small activation energy, Delta, indicate that a quasi-degenerate (metallic) state is stabilized in (TTFCOO)[(NH4+1)(1-x)(NH3)(x)], although the weakly temperature-dependent ESR linewidth indicates a localized characteristic. A novel type of carrier generation, self-doping, was discussed.