Eindimensionale Fehlordnung in Kristallen und ihr Einfluss auf die Röntgeninterferenzen. I. Berechnung des Fehlordnungsgrades aus den Röntgenintensitäten

The general theory is developed of X-ray scattering by crystals showing order in two translation directions but disorder in the third direction, the treatments previously published having proved inadequate for the interpretation of some single-crystal observations of the author. The solution of the problem is affected by the range of interaction between the arrangement of the neighbouring layers. General equations are here developed for a range of one layer. (In a second paper the special case of close-packed structures will be calculated for a range of three layers.) If the probability of faults is small, nearly ordered structures occur. These ordered structures are determined for a range of up to six layers. It is shown that the most probable layer type consisting of more than six layers of close-packed atoms is the SiC(I)-type (15 layers).