Backscattered electron Kikuchi patterns (BEKP) suitable for crystallographic phase analysis can be collected in the scanning electron microscope (SEM) with a newly developed charge coupled device (CCD) based detector. Crystallographic phase identification using BEKP in the SEM is unique in that it permits high magnification images and BEKPs to be collected from a bulk specimen. The combination of scanning electron microscope (SEM) imaging, BEKP, and energy dispersive x-ray spectrometry holds the promise of a powerful new tool for materials science.

CaF2 films have been grown epitaxially on (100) and (111) Si substrates by molecular beam epitaxy. These films have been characterized by electron microscopy, reflection high-energy electron diffraction, Rutherford backscattering ion channeling, and back-reflection Laue x-ray diffraction. In addition, chemical etching has been used to reveal dislocations and to delineate cracks. Film cracking appears to be related to crystalline perfection through misfit dislocation mobility. It is possible to grow high quality, (xmin=3.0%) single-crystal films on (111) Si which are free of cracks and atomically flat. However, the high free energy of the (100) surface in an ionic fluorite crystal prevents the growth of comparable CaF2 films on the (100) Si surface.

No abstract

No abstract

In recent years, grazing incidence angle attachments have been shown to be very useful in the phase identification of thin polycrystalline films. These devices are sold commercially as attachments to standard powder diffractometers. The attachment normally consists of a long soller slit assembly and a flat crystal monochromator. The soller slit with or without the monochromator is mounted on the diffracted beam side. In this paper we discuss the effects of different configurations from collimator to monochromator on diffraction data. An understanding of these effects is essential in order to obtain more reliable information on phase transformations, crystallite size, microstrain, and residual stress studies.