Etude des fautes d'empilement dans les kaolinites partiellement désordonnées. I. Modèle d'empilement ne comportant que des fautes de translation

By the use of a model with two kinds of stacking faults it is possible to explain quantitatively X-ray powder diffraction patterns of disordered kaolinites. The first kind of defect consists of random translations which limit coherent scattering regions in all hk directions except h = k = 0. The second kind consists of shifts between layers of ± nb/3 (n integer) which limit coherent scattering only in hk directions with k ≠ 3n. The comparison of calculated patterns with experimental (02,11) and (20,13) bands gives the proportions of different kinds of layer displacements in two disordered kaolinites.