Thin films of KCl, KBr, RbCl have been obtained by thermal evaporation on amorphous substrates with different deposition parameters. The crystalline structure and orientation have been determined, and the films resulted to be policrystals with high uniformity of orientation. Production of colour centres, achieved by irradiation with low-energy electrons, leads to F center concentrations barely observed in large crystals. The colouration kinetics is similar to that in the bulk, and shows after a maximum an exponential decay at high doses because of centre aggregation coupled to thermal effects. The films exhibit a bleaching process of the colour centres at room temperature, whose kinetics depends on the irradiation damage.
Ferri, M., Scacco, A., Somma, F., Montereali, R.m., Martelli, S., Petrocco, G., et al. (1992). CRYSTALLINE PROPERTIES AND COLOR-CENTERS IN ALKALI-HALIDE THIN-FILMS. RADIATION EFFECTS AND DEFECTS IN SOLIDS, 124(3), 313-323 [10.1080/10420159208220204].
CRYSTALLINE PROPERTIES AND COLOR-CENTERS IN ALKALI-HALIDE THIN-FILMS
SOMMA, Fabrizia;
1992-01-01
Abstract
Thin films of KCl, KBr, RbCl have been obtained by thermal evaporation on amorphous substrates with different deposition parameters. The crystalline structure and orientation have been determined, and the films resulted to be policrystals with high uniformity of orientation. Production of colour centres, achieved by irradiation with low-energy electrons, leads to F center concentrations barely observed in large crystals. The colouration kinetics is similar to that in the bulk, and shows after a maximum an exponential decay at high doses because of centre aggregation coupled to thermal effects. The films exhibit a bleaching process of the colour centres at room temperature, whose kinetics depends on the irradiation damage.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
