Calcite, Feldspars, Hardystonite, Pyromorphite, Scheelite, Zircon, Baddeleyite

Trivalent europium is an excellent ionic probe for materials and its luminescence properties are extensively studied. Eu is one of the mostly informative elements in mineralogy, especially when the ratio Eu /Eu may be assessed. Both oxidation states are luminescent, but the hnes of Eu in minerals are usually very weak and concealed by other centers. By steady state liuninescence spectroscopy its luminescence has been confidently detected only in scheehte and anhydrite (Tarashchan 1978 Gorobets and Rogojine 2001). 

Spin-orbital Crystal field coupling (Stark sublevels) (sublevels) 

4/ -configurational levels. The electric dipole-transitions are now no longer strictly forbidden and appear as weak lines in the spectra, the so-called forced electric-dipole transitions. Some-transitions, viz. with AJ = 2, 4, are hypersensitive to this effect. Even for small deviations from inversion symmetry, they appear dominantly in the spectriun (Blasse and Grabmaier 1994 Reisfeld and Jorgensen 1977 Reisfeld 1973). Intensity ratio analysis of the Dq Fi and Do p2 transition allows approaching the symmetry of the involved europium site. It is then possible to define the asymmetry ratio R  

Crystal field theory enables us to define certain parameters in order to characterize and distinguish the different europium site configurations. Crystal field parameter calculation involves several steps  

Determination of the three contributions, which are the three states of the crystal field for each environment. The contributions are labeled from the highest energy to the lowest one eo, e- and e+, respectively. The eo line is the thinnest and the most sensible to the excitation energy  

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