Anomalous transmission of x-rays in quasicrystals

The perfection of one of the quasicrystal grains with the highest degrees o f perfection was checked by means of x-ray diffractometry and x-ray topogra phy. Full widths at half maximum of de-convoluted reflectivity curves were close to the theoretical values and a partial Borrmann effect was clearly v isible in the measured reflection and transmission curves, whereas the topo graphs still showed rather strong intricate contrast, which means that stro ng deformations (defects) still exist in the grain. Consequently, dynamical effects like anomalous transmission were confirmed to exist in selected qu asicrystalline grains, but even then the structural quality is still far fr om being 'highly perfect'.