Single crystal diffraction by submicrometer sized kaolinite; Observation of Bragg reflections and diffuse scattering

For the first time single crystal diffraction experiments on individually mounted kaolinite crystals with volumes of 8 mu m(3) to 0.4 mu m(3) are reported. The diffraction patterns prove that no reflections violating the C-centering exist, confirming the space group C1 for kaolinite. Preliminary refinements confirm the structural model of kaolinite in C1. Non-hydrogen atoms could be refined anisotropically and the hydrogen positions could be refined as well. The diffraction patterns show diffuse scattering in streaks along OOl through hkl reflections with hk not equal zero, which is caused by stacking faults. The diffraction pattern of the smallest (0.4 mu m(3)) sample also reveals micro twinning and diffuse scattering. This sample consists of domains of left and right handed kaolinite.