ELNES across interlayers in SiC(Nicalon) fibre-reinforced Duran glass

This paper presents examples of the chemical bond characterization taken from microanalytical investigations of fibre-reinforced borosilicate glasses. Chemical bonding is examined across the fibre/matrix regions at nanometre resolution by analysing energy loss near edge structures (ELNES), particularly the Si-L(23) ELNES. In this context results are presented mainly concerning the chemical bonding of silicon with carbon and oxygen. To identify the bond state of silicon in the interfacial zone the Si-L(23) ELNES measured of standard specimens (silicon carbide, dioxide and oxycarbide) was used as a fingerprint. Along a line crossing the interlayer the bonding state of silicon is determined by recording series of EEL spectra. In addition, experimental ELNES results are compared with local densities of unoccupied states calculated by molecular orbital (MO) methods, where the calculations reflect the dependence of fine-structure features on the oxidation state.