Hoevers, H. F. C., Bento, A. C., Bruijn, M. P., Gottardi, L., Korevaar, M. A. N., Mels, W. A., et al. (2000). Thermal fluctuation noise in a voltage biased superconducting transition edge thermometer. Appl. Phys. Lett., 77(26), 4421–4424.
Abstract: The current noise at the output of a microcalorimeter with a voltage biased superconducting transition edge thermometer is studied in detail. In addition to the two well-known noise sources: thermal fluctuation noise from the heat link to the bath and Johnson noise from the resistive thermometer, a third noise source strongly correlated with the steepness of the thermometer is required to fit the measured noise spectra. Thermal fluctuation noise, originating in the thermometer itself, fully explains the additional noise. A simple model provides quantitative agreement between the observed and calculated noise spectra for all bias points in the superconducting transition.
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Gorokhov, G., Bychanok, D., Gayduchenko, I., Rogov, Y., Zhukova, E., Zhukov, S., et al. (2020). THz spectroscopy as a versatile tool for filler distribution diagnostics in polymer nanocomposites. Polymers (Basel), 12(12), 3037 (1 to 14).
Abstract: Polymer composites containing nanocarbon fillers are under intensive investigation worldwide due to their remarkable electromagnetic properties distinguished not only by components as such, but the distribution and interaction of the fillers inside the polymer matrix. The theory herein reveals that a particular effect connected with the homogeneity of a composite manifests itself in the terahertz range. Transmission time-domain terahertz spectroscopy was applied to the investigation of nanocomposites obtained by co-extrusion of PLA polymer with additions of graphene nanoplatelets and multi-walled carbon nanotubes. The THz peak of permittivity's imaginary part predicted by the applied model was experimentally shown for GNP-containing composites both below and above the percolation threshold. The physical nature of the peak was explained by the impact on filler particles excluded from the percolation network due to the peculiarities of filler distribution. Terahertz spectroscopy as a versatile instrument of filler distribution diagnostics is discussed.
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