Microanalytical and Structural Characterization of Optical Materials By Electron Microscopy and Related Specitroscopies

Abstract

The fine probe forming capabilities of an analytical electron microscope combined with the development of related spectroscopies, diffraction and imaging techniques, makes it possible to obtain structural and chemical information from multiphase materials at high spatial resolution. These microanalytical methods are described with relevant examples from our studies of compounds in the A1₂O₃-AIN pseudobinary system, a potential window material, low-pressure synthesized diamond, diamond-like carbon and hydrocarbon films. A comprehensive example of the characterization of a novel AION poltypoid structure (32H), illustrative of both the information content obtainable from these techniques at any particular level of resolution and the need to employ all the complementary methods of analysis, is discussed. Efforts to characterize a variety of diamond-like carbon films by the measurements of both the low-loss plasmon resonances and the fine strcture in the core-loss edges observable in the energy-loss spectrum, to obtain sp³/sp² ratios are outlined. The electronic structure of thin film diamonds, synthesized by a plasma enhanced chemical vapour deposition method, has been shown to be in agreement with band structure calculations.