The contrast from interfaces in the field-ion microscope

Abstract

A geometrical theory for interpreting the contrast across interfaces in field-ion images is developed in terms of bulk considerations. It is shown that the complete, partial or attempted matching of atomic planes across interfaces in the bulk results in recognizable ring matching effects in the image and it is further shown how such observations may be quantified to determine some aspects of the crystallography and line structure of the interface. Consideration is also given to the contrast to be expected from interfacial dislocations and ledges of various types, examples being given and interpreted in terms of the developed contrast theory.