Molecular Beam Epitaxy (MBE) is capable of producing a variety of high purity, epitaxial multilayer films
with well controlled interfaces. However, the conditions necessary for MBE growth somewhat restricts the choice
of useful materials. We discuss our material selection procedure for MBE-deposited x-ray optical multilayer
materials. This procedure takes into account factors such as chemical reactivity, thermal stability, and lattice match,.
as well as the maximum theoretical reflectivity obtainable with a given material pair. The present work consists
of a comprehensive study of elemental films, and a more detailed consideration of a few select compound systems.
Both the precise deposition contrOl possible with MBE, as well as the many in situ characterization methods,
combine to allow a high degree of control over the formation of interfaces. Our principle MBE system for x-ray
optics contains in situ Reflection High Energy Electron Diffraction (RHEED), Low Energy Electron Diffraction
(LEED), Auger Electron Spectroscopy (AES), X-Ray Photoelectron Spectroscopy (XPS) and Ion Scattering
Spectroscopy (ISS). An overview of the techniques used to analyze our films be given, including data from our
growth of epitaxial CoSi2 absorbing layers on Si (111) using a solid state reaction technique.