Publication at Faculty of Science, Faculty of Mathematics and Physics |
2010
Abstract
Samples of CaF2 irradiated for millions of years in nature were studied by several methods, including X-Ray diffraction, positron annihilation spectroscopy (PAS), photoluminescence spectroscopy (PLS) and transmission electron microscopy (TEM). It was found that the unexpectedly high density of radiation-induced defects present in the fluorite structure (documented by TEM) causes significant micro-strains.
Even annealing up to 450 °C cannot completely remove these micro-strains, which are stabilised by impurities. PAS and subsequent theoretical calculations revealed the behaviour of the defects during heating.
The PL spectra of irradiated fluorite were also interpreted.