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X-ray photoelectron emission microscopy (XPEEM) provides valuable chemical information at the micron or submicron level and has been successfully applied to a wide range of materials. We have initiated a study of metal–matrix composites (MMCs) using this technique, aimed at understanding the interfacial interactions that occur between the metal matrix and the ceramic reinforcement. The experiments have been performed on Ti/SiC (fiber) MMCs and SiC fibers. We have found that the method of preparing the sample plays a critical role in understanding the results of the measurements. Samples prepared by polishing and sputtering were examined using an electric-field imaging photoelectron microscope (EFIPM), and fractured samples were studied with a magnetic-field imaging photoelectron microscope (MFIPM). While the EFIPM exhibited exellent elemental contrast and resolution, the data were flawed by artifacts introduced by both the polishing and the sputtering. Although the spatial resolution of the MFIPM was lower than the EFIPM, the ability to study fractured samples greatly facilitated interpretation of the data, which revealed the intrinsic chemical states of the sample. These results will be interpreted in terms of the impact of sample preparation on the application of XPEEM to MMCs and other complex systems.

A purely electrostatic photoemission electron microscope with a bandpass energy filter is described. The electron optics are of a hybrid design, incorporating a high-voltage and high-magnification objective and intermediate lens, coupled to a low-voltage hemispherical capacitor configured as an achromatic imaging bandpass filter. The electron optical system design is described, along with initial performance tests. The instrument is used for both imaging X-ray absorption spectroscopy and photoemission spectroscopy.

X-ray absorption microscopy is used to study the surface of a mineral, ilmenite. High-quality surface-sensitive micrographs are easily obtained without special sample preparation beyond that usually used in preparing samples for optical microscopy. The X-ray micrographs show an expected lamellar domain structure that has a very strong contrast change at the iron and titanium L-edges. High-resolution spectroscopy from these two different regions reveals fine structure from iron atoms in two different charge states, and titanium in a single phase. A theoretical analysis and curve-fitting procedure is used to determine the precise stoichiometry of the structures in the two phases detected. These results show that quantitative surface chemistry studies can be performed on natural mineral samples using X-ray photoelectron emission microscopy.

Three closely related techniques, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and X-ray fluorescence spectroscopy, have become widely accepted as important tools for the study of the chemical composition and electronic properties of surfaces, overlayers, and interfaces. There is now a major effort to push these spectroscopic techniques into a new realm of applications with very high spatial resolution, at and below 1 μm. This results in a new set of probes which can create images of chemical composition with great subtlety. The field is growing rapidly as high brightness sources of X-rays become available. The goals and methods used in electron spectromicroscopy and related X-ray microscopies are discussed, and recent applications of instruments developed in the last few years are used to illustrate the strengths of these new microscopes.