Induction current of conducting polymers in magnetic field

我们发现聚苯胺薄膜处于导电状态时，在磁场作用下会感应电流。当薄膜具有电阻性时，检测不到电流。由于它在渗透阈势处逐步增加，所以不能用洛伦兹力的普通磁效应来解释。这可能是由于分子线圈处于导电状态引起的。感应电流随磁场强度、磁频率、薄膜厚度、掺杂水平和溶液pH值的变化而变化。这似乎与导电畴的宏观尺寸有关。作为磁场效应的延伸，我们开发了散射光的测量，以确定宏观域的大小。用可见激光照射恒电位聚苯胺薄膜，检测散射光强度与散射角的关系。散射光不是由于罗利散射，而是包含了干涉，通过分析光强随角度的变化，我们发现存在直径为5 μ m的导电团簇，可以通过显微镜检测到。粒径随潜在应用时间的增加而增加，并随对数时间呈线性变化。

We found that a polyaniline film in the electrically conducting state induced current when it was in magnetic field. The current was not detected when the film was resistive. Since it increased stepwise at a percolation threshold potential, it cannot be explained by ordinary magnetic effects by Lorentz force. It may be caused by molecular coils of the conducting state.The induced current varied with intensity with the magnetic field, the magnetic frequency, thickness of the film, a doping level, and pH of the solution. It seems to be related with a macroscopic size of conducting domains. As an extension of the magnetic field effect, we developed measurements of scattering light in order to determine the size of the macroscopic domains. A visible laser was shone on the potentiostated polyaniline films, and the scattering light intensity was detected as a function of scattering angles. The scattering light was not due to Raleigh scattering but included interference, By the analysis of variaqtion of the light intensity with the angles, we found the presence of conducting clusters 5 mum in diamter, which could be detcted through a microscope. The size increased with a time of potential application, showing a linear variation of the size with the logarithmic time.