Sputtering and coloration process in LiF thin layers induced by MeV ion bombardment

Beams of 2.0 MeV nitrogen ions, produced by a Van de Graaff generator, were used in order to create point defects in polycrystalline LiF thin films. T he radiation effects were examined by optical absorption, RES, PDMS and XPS methods. The concentration of the produced F-centers exhibits a saturation behavior, but decreases for doses higher than similar to 1 x 10(16)cm(-2). A fluorine sputtering yield Y similar to 3 was determined by using RES. Mo reover, XPS and PDMS techniques detected surface Li enrichment as a result of the ion bombardment. All these results denote the relevance of the sputt ering in the de-coloration process of LIF thin layers.