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

Abstract

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 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 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.

Platinum-enhanced graphitisation in sandwich structures of silicon carbide and borosilicate glass

“…8b) appears quite similar to that of silica showing an onset at about 104 eV and two distinctly split peaks at about 108.5 and 115.5 eV [42]. This clearly demonstrates the high content of SiO 2 in the reaction interlayer.…”

Cerium and boron chemistry in doped borosilicate glasses examined by EELS

“…Although Electron Energy Loss Spectra (EELS) has been used in recent years to study oxide glasses (Schneider et al, 1996;Fortner et al, 1997;Jiang et al, 2002Jiang et al, , 2003, the usefulness of this technique in the study of glass still seems to be insufficiently recognised. This is partially due to the success of bulk spectroscopies (with micro-to centimetre scale spatial resolutions) such as NMR, XAS, XPS, Raman spectroscopy (Stallworth and Bray, 1990;Fleet and Muthupari, 1999;Holland et al, 2003).…”

Using an Au interlayer to enhance electron field emission properties of ultrananocrystalline diamond films

“…Notably, in the EELS spectra, the peak near 109 eV corresponds to Si, [26][27][28][29] whereas those near 290 eV correspond to C (r and p bonds). 16,18 Figure 5(a) shows the EELS spectra for locations I, II, and III in the UNCD/Si films with the layer structure shown in the inset micrograph.…”

“…By using EELS spectrum I for location I as the internal standard for the Si materials, 26 EELS spectrum II for the interface layer can be unambiguously identified as the SiO 2 phase. 27,28 This spectrum contains some sp 2 -bonded carbon materials, presumably, the a-C layer. The SiO 2 layer is possibly the native oxide formed on the surface of the Si wafer during prenucleation.…”

“…5(b), revealing that the Au coating interacts with both the Si substrates and UNCD films in a more complicated way. Again, using EELS spectrum I as a reference profile for Si materials, 26 EELS spectrum II can be unambiguously identified as the SiO 2 layer, 27,28 which is at the interface between the Si and Au coating. In contrast, spectrum III indicates that the interfacial layer between the Au coating and the UNCD films is a SiC layer.…”