High-angle Kikuchi patterns

摘要: A cylindrical specimen chamber and camera have been used to study the high-angle Kikuchi patterns obtained by reflexion of electrons, energy 6 50 keV, from cleavage surfaces crystals with sodium chloride structure. Angles scattering ranging 0 164° were covered. The relative intensity pattern at different angles was measured using a photographic technique. distribution found become less steep as incident electrons decreased. In photographs taken large value glancing angle incidence, defect bands found, starting near shadow edge pattern; these changed excess higher scattering. most striking feature results is remarkable clarity highest produced such lead sulphide potassium iodide, constituents which relatively high elastic cross-section. marked contrast, low for lithium fluoride under same experimental conditions. An investigation width bands, visible over whole available angular range, showed that forming had within error 10%. possible mechanism discussed means can be diffused through efficiency, small angles, little loss energy.