X-Ray Source-Image Distortion Technique for the Study of Crystal Distortion and Vibration

Publisher Website
Google Scholar
Abstract
A technique is described which permits graphic display and quantitative determination of ultrasonic oscillation amplitudes, and of warping and other macroscopic strains, in crystals. An x‐ray ``source image'' appears superimposed on the crystal image formed by one diffracted beam from a stationary crystal. ``Source‐image'' distortion (SID) occurs on reflection from distorted regions of the crystal. X‐ray sources ranging from 100‐μ spots to 15‐mm line sources interrupted by Soller slits have been used. The latter experimental arrangements bear some similarities to those described by Cullity and Julien, by Barth, and by Carlson and Wegener. Lattice tilts of ∼1′ and lattice strain variations (Δd/d) of ∼10−4 can be routinely detected and separately identified. The underlying crystal image often contains useful topographic information of limited quality. SID photographs showing distortion produced in quartz plates by mounting clips, cements, cracks, and piezoelectric oscillations are presented. An example of direct measurement and mapping of vibrational amplitudes, e.g., 650±25 Å in one case, in piezoelectrically oscillating crystals is given. Oscillation mode characterization has been aided by the SID demonstration of a 180° phase relation in some cases and by both SID and topographic display of the pattern of vibrational activity.

This publication has 3 references indexed in Scilit: