Using terahertz time-domain spectroscopy, the frequency-dependent conductivities of polyaniline emeraldine salt-polyethylene (PAni-PE) pellets were measured at different mass concentrations. THz conductivities were compared to the behavior of DC conductivities measured using impedance spectroscopy. The DC conductivity behavior with mass concentration showed a low percolation threshold. The frequency-dependent behavior in the THz region follows the Mott-Davis behavior which shows stronger correlation at higher PAni concentration. At the same time, the conductivity increases exponentially with increasing PAni concentration over the frequency range studied without an apparent percolation threshold. The mechanisms in the two regions studied suggest that there is more dominant localization in the THz regime in contrast with a more dominant percolative transport in the Hz-MHz region. Temperature-dependent measurements showed a decreasing value of parameter S with increasing temperature consistent with a correlated barrier hopping model. Lastly, the parameter S increases in magnitude with a decreasing amount of PAni in the composites reflective of varying conducting and nonconducting compositions.

中文翻译：

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聚苯胺翡翠盐-聚乙烯微丸中太赫兹电导率的温度依赖性

使用太赫兹时域光谱仪，在不同质量浓度下测量聚苯胺翡翠盐-聚乙烯（PAni-PE）颗粒的频率依赖性电导率。将THz电导率与使用阻抗谱法测量的DC电导率行为进行了比较。质量浓度下的直流电导率行为显示出较低的渗透阈值。THz区域中的频率相关行为遵循Mott-Davis行为，该行为在较高的PAni浓度下表现出更强的相关性。同时，在研究的频率范围内，电导率随PAni浓度的增加呈指数增长，而没有明显的渗漏阈值。在研究的两个区域中的机制表明，与在Hz-MHz区域中更占优势的渗透传输相比，在THz体制中具有更占优势的定位。与温度有关的测量表明参数值减小温度升高的S符合相关的势垒跳跃模型。最后，随着复合材料中导电和非导电成分的变化，参数S随PAni数量的减少而增加。