Optical Reflectance of Polymeric Sulfur Nitride Films from the Ultraviolet to the Infrared

We report the first synthesis of chemically pure polymeric sulfur nitride [${\left(\mathrm{SN}\right)}_x$]. The optical reflectance of well-characterized films of this polymeric solid has been measured from the near ultraviolet (30 000 ${\mathrm{cm}}^{-1\mathrm{}}$) to the far infrared (500 ${\mathrm{cm}}^{-1\mathrm{}}$). Metallike reflectance is observed in the infrared through the visible region with a well-defined plasma minimum near 22 000 ${\mathrm{cm}}^{-1\mathrm{}}$, corresponding to light polarized parallel to the polymer chain axis. The Drude-Lorentz model is used to analyze the data, and the physical implications of the resultant parameters are discussed.