抄録
The anomalous effect reported by Fukushima (E. Fukushima; Acta Cryst. 459 (1954) 7), i.e. a large enhancement of X-ray reflection intensity at the boundary of etched and ground regions in quartz crystal slab, is studied by a double crystal spectrometer. The difference can not be found in line width of reflection curves at the ground region and at the boundary region. Lattice bending is not detected at the boundary. It is not larger than 10″, if it exists. The anomalous enhancement is erased by etching the crystal surface for several seconds. This anomalous effect can be observed also in NaClO3 crystal and calcite but the enhancement is very small in the latter crystal. It is concluded that the anomalous enhancement is due to a reduction of primary extinction caused by elastic distortion accumulated at the boundary region.
