A light induced configurational change of FA centres in Li doped KCl-KBr crystals |
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| Authors: | P Ketolainen P Silfsten |
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| Institution: | 1. Department of Physics , University of Joensuu , P.O. Box 111, FIN-80101 , Joensuu , Finland;2. Department of Information Technology , Lappeenranta University of Technology , P.O. Box 20, FIN-53851 , Lappeenranta , Finland |
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| Abstract: | Abstract Spectroscopic properties of FA centres in Li doped KCl-KBr mixed crystals were studied. At low temperature light induced spectral shifts, for the FA1 hand towards lower energy and for the FA2 band towards higher energy, were observed. The shifts are proposed to be due to a configurational change where the electron occupied vacancy finds a new location in relation to the neighbouring chlorine and bromine ions. The recovery to the original configuration, obtained in the F → FA conversion, is a temperature activated process. |
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| Keywords: | alkali halides mixed crystals colour centres FA centres |
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