Strontium fluoride

] Another proposal is that polarisation of the electron core of the barium atom creates an approximately tetrahedral distribution of charge that interacts with the Sr-F bonds. [Core Distortions and Geometries of the Difluorides and Dihydrides of Ca, Sr, and Ba Bytheway I, Gillespie RJ, Tang TH, Bader RF Inorganic Chemistry, Vol.34, No.9, 2407-2414, 1995 doi|10.1021/ic00113a023]

Properties

It is almost insoluble in water (its K_sp value is approximately 4.33x10^-9 at 25 degrees Celsius.
It irritates eyes and skin, and is harmful when inhaled or ingested.
Similar to CaF₂ and BaF₂, SrF₂ displays superionic conductivity at elevated temperatures. [http://www.newmet.co.uk/Products/koch/strontium.php http://www.newmet.co.uk/Products/koch/strontium.php] ]
Strontium fluoride is transparent to light in the wavelengths from vacuum ultraviolet (150 nm) to infrared (11 µm). Its optical properties are intermediate to calcium fluoride and barium fluoride. [http://www.crystran.co.uk/products.asp?productid=155 http://www.crystran.co.uk/products.asp?productid=155] ]

Uses

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.

References