%0 Journal Article %T Effect of natural irradiation in fluorites: possible implications for nuclear waste management? %A Vl£¿ek V %A Sk¨¢la R %A Goli¨¢£¿ V %A Drahokoupil J %J Journal of Geosciences %D 2012 %I %R 10.3190/jgeosci.110 %X Samples of naturally irradiated fluorite have been analyzed by means of X-ray powder diffraction analysis (XRPD), differential scanning calorimetry (DSC) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The diffraction patterns of all irradiated samples show peak broadening caused by micro-strain, which was evaluated by Williamson-Hall method, and an increase in the unit cell parameter. The DSC analysis showed an exothermic peak at 273 C corresponding to enthalpy change about 16 kJ.mol-1. This value is an order of magnitude higher than calculated change due to unit cell volume increase that is only 2 kJ.mol-1. The LA-ICP-MS did not show any significant substitutions, which might account for observed unit-cell parameter increase. The results have shown that high radiation doses lead to formation of defect clusters. %K fluorite %K irradiation %K X-ray diffraction %K differential scanning calorimetry %K defects %K real structure %U http://www.jgeosci.org/content/jgeosci.110_vlcek.pdf