Detection of crystal lattice defects in microranges of copper by X-ray interferences

The lattice source interferences (LSI) or Kossel technique and the divergen t beam X-ray interferences (DBI) or pseudo-Kossel technique are highly sens itive to the real structure in the microrange of the crystal lattice. Both methods complement each other, owing to their geometrically different diffr action regions. Mechanically ground and polished Cu single crystals with di fferent crystallographic orientations ([100], [110], [621], [694]) and two polycrystalline Cu specimens were chemically etched stepwise with FeCl3. 6H (2)O. After each etching time, divergent beam X-ray patterns of the crystal s were taken and in some cases lattice source interferences pattern also. I t was possible to observe the real structure as a function of the depth, be cause the information comes from a depth of about 2-5 mu m for LSI and 50-1 00 mu m for DBI. The DBI patterns show, for instance, for Cu [100], sharp i nterference lines from regions up to 40 mu m deep. With increasing depth th e crystal lattice reveals the real structure only and not the deformation e ffect caused by polishing.