The Application of Electron Energy Loss Spectroscopy in Glass - Ceramic Microstructural Analysis

Abstract

The identification of unknown phases in crystallized glasses or ceramics has been difficult because the phases are generally composed of many elements; they crystallize into low-symmetry lattices; they contain numerous impurities, which may alter crystal structure or allow the observation of metastable phases; and they are not well represented in standard compilations of crystal data. Compounding the problem is the fact that energy- dispersive x-ray analysis (EDX) for elemental content can not be employed for elements with Z<11. This eliminates any possibility of qualitative analysis of the important Li, Be, and B glasses as well as determination of O, C and N content. Electron Energy Loss Spectrometry (ELS) has been shown to be a powerful method for the analysis of light elements. The ELS method is far more efficient at detecting light elements than x-ray detection, because the yield of energy loss electrons to inner shell excitation and ionizations is unity and because the electrons, which have lost energy encountering the sample, are scattered through very small angles, with the result that collection efficiencies are high.