X-ray Diffraction Study of Low- and High-Angle Misorientations in LiF Crystals during Creep

Abstract

Low-and high-angle lattice misorientations in LiF single crystals subjected to tensile deformation in the temperature range 573–973 K were studied using the following x-ray diffraction techniques: the ω-scanning method, the Laue method, and the Kossel and Fujiwara widely divergent beam (WDB) methods. The fraction of the high-angle misorientation is shown to be low at low temperature, where a block structure is absent, and at high temperature, where blocks are large (∼100 μm). The high-angle misorientation increases with strain faster than the low-angle misorientation. The misorientations measured by different techniques can differ because of the different areas which are illuminated by an x-ray beam and over which the misorientations are averaged. The results obtained are compared with available data on the structure of deformed alkali-halide crystals.