Erholungsvorgänge in UV-bestrahltem Silberchlorid

The formation of defects in AgCl single crystals under UV and X-ray exposure and their thermal annealing are studied by measuring the optical density, the lattice parameter change, the X-ray Ag-reflection and by electronmicroscopical observations. Specks of crystalline silver are found to be produced at the surface of the crystals as well as in the interior. According to surface and volume darkening the isochronal annealing curves exhibit two stages. The activation energy for stage I, (0,59±0,08) eV, is suggested to be the energy for the thermal formation of electrons and Ag ₀ ⁺ -ions from Ag-aggregates. Stage II appears when the crystal is annealed in chlorine at above 523 °K. It is due to the regeneration of silver at the surface, where chlorine was able to leave the crystal during exposure.