Fine Structure and semi ordered structures : Extended energy loss fine structure investigations of semi ordered materials

Sammanfattning: This thesis is based on structure determinations of solid materials with Extended energy loss fine structure (EXELFS) analysis. In this method the ionisation edges of a material recorded in an electron microscope are studied. The focus is on different hard materials. The materials and their properties as well as the methodology of electron energy loss spectroscopy (EELS) and EXELFS analysis is discussed. Analysis of a hard and elastic carbon nitride thin film and magnesium silicate aluminium precipitates have been performed. The possibilities and limitations of the method have been investigated in two works. The effect of curved carbon structures, like fullerenes, on the results has been simulated and evaluated. In the second work the possibility to determine the coordination numbers with EXELFS has been investigated. Finally theoretical simulations of the near edge of the carbon 1s ionisation edge has been simulated to explore the possibility of thus determining the position of the carbon atom in a hexagonal BN lattice.