The Form of the X-Ray Diffraction Bands for Regular Crystals of Colloidal Size

Abstract

The form of the diffraction bands of a very fine uniform crystalline powder has been computed for the (1, 0, 0), the (1, 1, 0) and the (1, 1, 1) planes for cubical and octahedral crystals of the regular system. The shape of the bands is approximately that of the Gauss error curve. Both the shape and the half intensity breadth vary from band to band and the variations are characteristic of the shape of the crystals. There is definite correlation between the form of the band and the direction of the corresponding Bragg planes with respect to the external features of the crystal. The mean breadth of the bands is nearly the same for cubical and octahedral crystals having the same volume. The values of the constant of Scherrer's equation are in general smaller than those computed by other investigators for the cubical case.