This paper is focused on the formation mechanisms and the general behavior of negative ions in low pressure radio-frequency (RF) plasmas operated in a mixture of argon and aniline vapor. This type of plasma is mostly used for the synthesis of polyaniline, one of the most studied conductive polymers. Experiments based on mass spectroscopy measurements reveal the necessity to have a thin layer of plasma synthesized polyaniline on the electrodes to produce negative ions through complex surface reactions.
View Article and Find Full Text PDFIn this paper, an original homemade system is presented in detail for the electrical and thermoelectrical characterizations of several types of materials from bulk to thin films. This setup was built using a modulated CO laser beam to probe the thermoelectric properties at different depths below the surface. It allows a simultaneous measurement of the electrical conductivity () and the Seebeck coefficient (), from room temperature up to 250 °C.
View Article and Find Full Text PDFDust particle growth in a plasma is a strongly disturbing phenomenon for the plasma equilibrium. It can induce many different types of low-frequency instabilities that can be experimentally observed, especially using high-speed imaging. A spectacular case has been observed in a krypton plasma where a huge density of dust particles is grown by material sputtering.
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