Abstract:
Amorphous carbon films prepared by Chemical Vapor Deposition Method are widely used in oil industry as a protective layer of optical fibers in harsh environments. Clearly, the structural behavior of carbon coating surfaces is straightforward linked to synthesis conditions such as temperature, reactor geometry, precursor gas, fiber drawing speed. In this paper, we report on the effect of precursor gas on the structure and chemical properties of prepared carbon films. This is evidenced through the observed a temperature-dependent hysteresis of dc conductivity that magnitude is about a few percent of the initial resistance of carbon coating. Appearance of hysteresis loop can be explained possible interaction of carbon film with molecules from surrounding media that was revelated by Raman spectroscopy. In order to characterize of the intrinsic heterogeneity of carbon coating prepared by different precursor gases a new spectroscopic parameter was introduced.