TEMPERATURE-DEPENDENT ABSORPTION SPECTROMETRY ON LIF-MG,TI

Optical absorption spectra of irradiated single crystals of LiF:Mg,Ti have been studied while the sample temperature has been raised during the measurement. Nine absorption bands could be distinguished. Careful computerized curve fitting of the spectra allow for the behaviour of the various bands during heating. The absorption spectra have been com pared with spectra measured after a pulse anneal. Clear differences ha ve been observed between the continuous and pulse anneal spectra indic ating that the defect state of the sample at room temperature after a pulse anneal is not the same as during TL emission. A striking result is the rise and fall during the heating process of the absorption band s at 4.50 eV (not noticed before) and 5.54 eV (known from the literatu re). Similarities between the pulse and continuous anneal spectra have been observed for the behaviour of the 4.00 and 5.10 eV bands. (C) 19 98 Elsevier Science Ltd. All rights reserved.