Strontium fluoride, SrF2, also called strontium difluoride and strontium(II) fluoride, is a fluoride of strontium. Another proposal is that polarisation of the electron core of the strontium atom creates an approximately tetrahedral distribution of charge that interacts with the Sr-F bonds. It is a stable white brittle crystalline solid with melting point of 1477°C and boiling point 2460°C. Strontium Fluoride has only specialist applications. Optically, Strontium Fluoride has properties intermediate to Calcium and Barium Fluoride.
The solid adopts the fluorite structure. In the vapour phase the SrF2 molecule is non-linear with an F-Sr-F angle of approximately 120°. This is an exception to VSEPR theory which would predict a linear structure. Ab initio calculations have been cited to propose that contributions from d orbitals in the shell below the valence shell are responsible.
Strontium fluoride is used as an optical material for a small range of special applications, for example, as an optical coating on lenses and also as a thermoluminescent dosimeter crystal. Another use is as a carrier of strontium-90 radioisotope in radioisotope thermoelectric generators.