Defects in CaF2 caused by long-time irradiation and their response to annealing

Vojtech Vlcek (1, 2) , Jakub Cizek (3) , Jan Drahokoupil (4) , Jan Valenta (3) , Nobuyoshi Miyajima (1) , Roman Skala (5)

1 BGI - Bayerisches Geoinstitut
2 Institute of Geochemistry, Mineralogy and Mineral Resources
3 Faculty of Mathematics and Physics [Praha/Prague]
4 Institute of Physics
5 Institute of Geology

Samples of CaF2 irradiated for millions of years in nature were studied by several methods: X-Ray Diffraction, Positron Annihilation Spectroscopy (PAS), Photoluminescence Spectroscopy (PLS), and Transmission Electron Microscopy (TEM). It was shown 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. The PAS and subsequent theoretical calculations revealed the behaviour of the defects during heating. The PL spectra of irradiated fluorite were interpreted as well.

Mots clés: Physical Sciences

Vojtech Vlcek, Jakub Cizek, Jan Drahokoupil, Jan Valenta, Nobuyoshi Miyajima, et al.. Defects in CaF2 caused by long-time irradiation and their response to annealing. Philosophical Magazine, 2010, 90 (20), pp.2749-2769. ⟨10.1080/14786431003745385⟩. ⟨hal-00596600⟩