Knowledge Bank

“It is well-known that the absorption properties of LiF crystals are dependent upon growth techniques. In particular, crystal growth in air results in isomorphous substitution of fluorine ions by OH-groups and gives rise to the formation of forger light-scattering imperfections. As against that, there are vacuum-grown crystals which do not exhibit imperfection of this kind, even if produced from the same raw material as those grown in air. Investigations are made of the effect of x-rays, deuterons, protons and electrons on the coloration spectra and fluorescence spectra of both kinds of crystals. Both in absorption and emission, dependence of spectra upon the growth techniques and the kind of radiation used for coloration was of no significance. Coloration spectra produced by deuterons were investigated in dependence upon the petition in the colored layer. Fluorescence was not only excited in the $R1-,R2-$ and M-bands bill also in the F-BAND. Verification of coloration properties produced by radiation in additively and electrolytically colored crystals failed of success, as these methods did not allow of attaining selective absorptions. The results can be interpreted by assuming intrinsic lattice imperfections. In the concluding section results are discussed on broad lines.”